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NASA CR-II2I40 VIBRATION AND DAMPING OF LAMINATED, COMPOSITE-MATERIAL PLATES INCLUDING THICKNESS-SHEAR EFFECTS Final Report (Part II) NASA Research Grant NGR-37-003-055 by C.W. Bert & C.C. Siu School of Aerospace, Mechanical and Nuclear Engineering The University of Oklahoma Norman, Oklahoma 73069 Prepared for National Aeronautics -.and Space Administration Washington, D.C. \ March 1972 https://ntrs.nasa.gov/search.jsp?R=19720022240 2018-02-12T19:37:57+00:00Z

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NASA CR-II2I40

VIBRATION AND DAMPING OF

LAMINATED, COMPOSITE-MATERIAL PLATES

INCLUDING THICKNESS-SHEAR EFFECTS

Final Report (Part II)NASA Research Grant NGR-37-003-055

by

C.W. Bert & C.C. SiuSchool of Aerospace, Mechanical and Nuclear Engineering

The University of OklahomaNorman, Oklahoma 73069

Prepared for

National Aeronautics -.and Space AdministrationWashington, D.C.

\ March 1972

https://ntrs.nasa.gov/search.jsp?R=19720022240 2018-02-12T19:37:57+00:00Z

1 NR/(SANCR- II2I404. Title and Subtitle

VIBRATION AND DAMPING IMATERIAL PLATES INCLUDIN

2. Government Accession No.

DF LAMINATED, COMPOSITE-IG THICKNESS -SHEAR EFFECTS

7. Author(s)

C. W. Bert and C. C. Siu

9. Performing Organization Name and AddressSchool of Aerospace, Mechanical, and Nuclear EngineeringThe University of OklahomaNorman, Oklahoma 73069

12. Sponsoring Agency Name and Address

National Aeronautics and Space AdministrationWashington, D.C. 20546

3. Recipient's Catalog No.

5. Report Date

6. Performing Organization Code

8. Performing Organization Report No.

10. Work Unit No.

501-22-03-0311. Contract or Grant No.

NGR-37-003-05513. Type of Report and Period Covered

Contractor Report14. Sponsoring Agency Code

15. Supplementary Notes

16. Abstract

An analytical investigation of sinusoidally forced vibration of laminated, anisotropicplates including bending-stretching coupling, thickness-shear flexibility, all three typesof inertia effects, and material damping was conducted. The analysis begins with theanisotropic stiffness and damping constitutive relations for a single layer and proceedsthrough the analogous relations for a laminate. Then the various types of energyand work terms are derived and the problem is formulated as an eigenvalue problemby application of the extended Rayleigh-Ritz Method. The effects of thickness-sheardeformation are considered by the use of a shear correction factor analogous to thatused by Mindlin for homogeneous plates. The general analysis is applicable to plateswith any combination of natural boundary conditions at their edges.

Natural frequencies of boron/ epoxy plates calculated on the basis of two differentresonance criteria (peak-amplitude and modified Kennedy-Pancu techniques) and theassociated nodal patterns are in good agreement with previously published experimentaldata.

17. Key Words (Suggested by Author(s))

Composite materialsVibration dampingStiffnessVibration , Micromechanics

19. Security dassif. (of this report)

Unclassified

18. Distribution Statement

Unclassified - Unlimited

20. Security Qassif. (of this page)

Unclassified21. No. of Pages 22. Price*

245

For sale by the National Technical Information Service, Springfield, Virginia 22151

VIBRATION AND DAMPING OF

LAMINATED, COMPOSITE-MATERIAL PLATES INCLUDING THICKNESS-

SHEAR EFFECTS

CONTENTS

Page

ABSTRACT lv

SYMBOLS vi

I. INTRODUCTION 1

1.1 Introductory Remarks 1

1.2 A Brief Survey of Selected Vibratlonal Analyses ofLaminated Plates 4

II. FORMULATION OF THE THEORY 9

2.1 Hypotheses 9

2.2 Kinematics 10

2.3 Stiffness Constitutive Relations 11

2.4 Strain Energy 15

2.5 Damping Coefficients and Dissipative Energy 17

2.6 Kinetic Energy 18

2.7 Work Done by External Forces 19

2.8 Application of the Extended Rayleigh-Ritz Method 20

2.9 Reduction to Matrix Form 23

III. DERIVATION OF THICKNESS-SHEAR FACTORS FOR LAMINATES 25

3.1 Static Approach 26

3.2 Dynamic Approach 30

IV. MODAL FUNCTIONS USED FOR VARIOUS PLATE BOUNDARY CONDITIONS 32

4.1 Simply Supported on All Edges 32

4.2 Fully Clamped on All Edges 33

4.3 Free on All Edges 34

V. NUMERICAL RESULTS AND COMPARISON WITH RESULTS OF OTHERINVESTIGATORS 35

5.1 Thickness-Shear Factors for Laminates 35

5.2 Plate Simply Supported on All Edges 36

5.3 Plate Free on All Edges 38

VI. CONCLUSIONS 42

APPENDIXES

A. NOTATION AND TRANSFORMATION FOR ELASTIC COEFFICIENTS 44

B. MODELS AND MEASURES OF MATERIAL DAMPING 50

Bl. Mathematical Models for Material Damping 50

B2. Measures of Material Damping 62

B3. Inter-Relationships Among Various Measures of Dampingfor Homogeneous Materials 67

C. DERIVATION OF ENERGY DIFFERENCE 76

D. COMPLETE ENERGY EXPRESSIONS 79

Dl. The Energy Difference 79

D2. Equations for Minimizing the Energy Difference 80

E. DERIVATION OF THICKNESS-SHEAR FACTOR FOR THE THREE-LAYER,SYMMETRICALLY LAMINATED CASE USING THE DYNAMIC APPROACH 85

El. Dynamic Elasticity Analysis of an Individual LayerUndergoing Pure Thickness-Shear Motion 85

ii

E2. Dynamic Elasticity Analysis for Three-Layer,Symmetrically Laminated Case gg

E3. Dynamic Analysis of a Symmetrically LaminatedTimoshenko Beam Undergoing Pure Thickness-Shear Motion 88

E4. Determinations of the Thickness-Shear Factor 91

F. COMPLEX STIFFNESS COEFFICIENTS FOR A LAMINATE HAVING ALTERNATINGPLIES OF TWO DIFFERENT COMPOSITE MATERIALS 92

Fl. Introduction 92

F2. Analysis 93

G. IDENTIFICATION OF INTEGRAL FORMS 100

Gl. Trigonometric Integrals 100

G2. Combination Trigonometric-Beam Type Integrals 107

H. EVALUATION OF EXPERIMENTAL METHODS USED TO DETERMINE MATERIALDAMPING IN COMPOSITE MATERIALS 109

I. DISCUSSION ON SYMMETRY OF THE ARRAY OF CONSTITUTIVE COEFFICIENTS 123

J. COMPUTER PROGRAM DOCUMENTATION 126

REFERENCES , 128

TABLES 147

FIGURES 157

COMPUTER PROGRAM LISTING 180

iii

ABSTRACT

This report is concerned with analytical investigation of si-

nusoidally forced vibration of laminated, anisotropic plates including

bending-stretching coupling, thickness-shear flexibility, all three

types of inertia effects, and material damping.

In the analysis the effects of thickness-shear deformation are

considered by the use of a shear correction factor K, analogous to that

used by Mindlin for homogeneous plates. Two entirely different approaches

for calculating the thickness-shear factor for a laminate are presented.

Numerical examples indicate that the value of K depends on the layer

properties and the stacking sequence of the laminate.

The general analysis is applicable to plates with any combination

of natural boundary conditions at their edges. The analysis begins with

the anisotropic stiffness and damping constitutive relations for a single

layer and proceeds through the analogous relations for a laminate. Then

the various types of energy and work terms are derived and the problem is

formulated as an eigenvalue problem by application of the extended

Rayleigh-Ritz method.

The first five resonant frequencies of boron/epoxy plates with all

edges free are calculated on the basis of two different resonance criteria:

the peak-amplitude and modified Kennedy-Pancu techniques. The results show

that the resonant frequencies obtained by the two techniques differ by only

a very small amount, and are in good agreement with the results obtained

iv

both experimentally and analytically by Clary. Furthermore, the nodal

patterns obtained agree satisfactorily with those of Clary. Finally,

the damping values in this investigation are in good agreement with the

experimental ones obtained by Clary.

SYMBOLS

A cross-sectional area

AQ area involved in shear-stress integration (fig. 8)

A.,B constants depending upon the boundary conditions (Appendix E)

Aj hereditary constants, eq. (B-21)

A.. stretching stiffness of the plate

a length of plate

a(x.) ,a(x2) wave amplitudes at positions x. and x«

a.,a _,a free-vibration amplitudes corresponding to the i-th,1 (i+l)th, and (i+n)th cycles

a initial amplitude

B. . bend ing-stretching coupling stiffness of the plate

B. . complex stiffness coefficient

b width of plate

b material damping coefficient defined in eq. (B-10)

b critical material damping coefficient

C, damping coefficient defined in eq. (B-22)

C' damping coefficient defined in eq. (B-8)

C. constants depending upon the initial conditions

C. . Cauchy elastic coefficient

C.. complex version of C..

C ' effective stiffness coefficients defined followingJ ' eq. (F-7)

C ,C characteristic parameters tabulated in ref. 44m n

c viscous damping coefficient

VI

c Kelvin-Voigt complex damping coefficient

c critical value of c

c shear wave-propagation velocitys

D total dissipative energy

D energy dissipated per unit of plate area

D.. bending and twisting stiffnesses of the plate

D.. complex version of D..

E Young's modulus

E.. . ,E_2 Young's moduli in the x,y directions

Ei(u) the exponential integral defined in eq. (B-18)

e base of the natural logarithms, e ~ 2.7183

F, damping force

F spring forceS

F exciting force amplitude

AF horizontal shear force per unit width

F . thickness-shear stiffnesses of the plate

F.. complex stiffness coefficients associated with F

|fI generalized-force column matrix

g loss tangent

g1 parameter of the Biot model

g, dimensionless geometric parameter defined in ref. 35

g. ,etc. subscripted loss tangents where the subscripts (i.e.refer to the associated stiffness; for example, g^iisignifies the loss tangent associated with thelongitudinal stretching stiffness

H factor - (h/m)

HPMF half-power magnification factor

H factor = H/u,n

vii

H ,H thickness fractions of layers a and b, respectively

h total thickness of the plate; parameter in eq. (H-2)

I integral form defined in Appendix G

i unit imaginary number =• /-I

K thickness shear factor

K factor defined in eq. (H-10)

K complex-flexibility factor defined in eq. (F-15)

K. . composite shear coefficient

k spring rate

k complex spring constant

k' stiffness coefficient associated with the total in-plane force

k11 C1 e m (C1 and m are constants)

ic Kelvin-Voigt complex stiffness defined in eq. (B-3)

L effective length of spring

L amplitude of Lagrangian energy difference

L complex-stiffness factor defined in eq. (F-16)c

-f.n natural logarithm

log logarithm with base 10

mass matrix

M stress couples, moment per unit width

MF,MF' magnification factors defined in eqs. (B-38) and (B-16)

m damping exponent defined in eq . (B-22)

m mass

tn,n cos 9, sin 0

m ,m. ,nu mass per unit of plate area, first moment of mass perunit area, second moment of mass per unit area

viii

N.. membrane stress resultants, force per unit width

n degree of heredity

Q quality factor ? reciprocal of the dimensionless bandwidth

Q. thickness-shear stress resultant

Q.. reduced stiffness coefficients transformed to platecoordinates (x,y); see eq. (A-16)

*Q. . reduced (plane-stress) stiffness coefficients with re-

spect to material symmetry axes (X,Y); defined in eq. (A-6)

q normal pressure acting on plate

R density ratio (;= p^/p(2))

RMF resonant magnification factor

§ complex flexibility defined in eq. (F-22)

fS] complex stiffness matrix

T kinetic energy; period of damped oscillation (Appendix Bonly)

T. kinetic energy per unit of plate area

[T ] transformation matrix defined in eq. (A-12)

t time

t|,t~ two different specific values of time

U strain energy

U. strain energy per unit of plate areaA

U, energy dissipated per cycle

U, damping energy per cycle and per unit of volumedv

U undetermined longitudinal-displacement parametersrun

U shear strain energys

U1 shear strain energy associated with equivalent uniform,longitudinal thickness-shear strain

U strain energy per unit of plate volume

ix

u,v,w displacements in the x,y,z directions

u ,v ,w displacements of middle surface in x,y,z directionso o o

u displacement amplitude of vibration

u1 trasient solution in eq. (B-70)

u static displacement; see Appendix 8o t

V volume

V undetermined transverse-displacement parameter

v spatial attenuation constant defined in eq. (B-33)8

v temporal decay constant defined in eq . (B-30)

W total work done

W undetermined normal-displacement parametermn

X,Y,Z coordinates of the material-symmetry axes

x,y,z rectangular coordinates in the longitudinal, transverse,and thickness directions

x. ,x? two different specific values of position

Z ,Z characteristic parameters tabulated in ref. 44m' n

z,,z thickness-direction coordinates of outer and inner faces*~l of the k-th layer

•j > column matrix

[ j square matrix

normalized arguments in the x,y directions

heredity constants in eq. (B-21)

C^/C^ in Appendix E only

loss angle defined in eq . (B-27)

spatial attenuation rate defined in eq. (B-34)s

v decay rate defined in eq. (B-31)

A comples factor defined in eq. (F-22)

o logarithmic decrement defined in eq. (B-28)

6 logarithmic attenuation defined in eq. (B-32)s

e Biot parameter in eq. (B-17)

e . . strain components with respect to x,y axes

eTT strain components with respect to X,Y axesL J

e strain corresponding to longitudinal thickness-shearXZ action (Section III and Appendix E)

longitudinal thickness-shear strain weighted accordingto eq. (55)

damping ratio

XZ to eq. (55)

9 angle of orientation of an individual layer

<t . . curvature changes

u parameter (* t / . i< )

v Poisson's ra t io

V12 ,v?1 major and minor in-plane Poisson's ratios

| generalized coordinate

\f \ column matrix representing generalized displacementsL mnJ

rt pi *-• 3.1415962

p density

V> summation symbol

6 stress amplitude

3.. stress components with respect to x,y axes

0 stress components with respect to X,Y axesi. J

T dummy time variable in eq . (B-19)

>!> assumed modal function

4>(t) hereditary kernel defined in eq . (K-21)

xi

V ,¥xmn ymn

x y

0

phase angle between response and exciting force

undetermined rotation parameters

angles of rotation in the xz and yz planes

dimensionless frequency (=

Q at half-power points

OJ

Superscripts:

(k)

Subscripts:

k

t,

m

n

R

circular frequency of vibration

natural frequency

angular frequencies defining the half-power pointsof the frequency spectrum

denotes a typical kth layer

denotes a damping quantity

denotes differentiation with respect to time

denotes that the quantity is an amplitude

refers to the middle surface of the plate

denote the respective imaginary and real parts ofa complex quantity

denotes partial differentiation with respect to thevariable following the comma, i.e. UQ x = ouo/5x

integers ; k = 1,2,... K

integers ; /. = 1,2,... L

integers ; m = 1,2,... M

integers ; n = 1,2,... N

denotes resonance

xii

SECTION I

INTRODUCTION

1.1 Introductory Remarks

The continuing demand for increased structural efficiency in many

advanced aerospace vehicles has resulted in development of laminated

structures made of advanced fiber-reinforced composite materials, such as

boron-epoxy, graphite-epoxy and boron-aluminum (reference 1). One of the

most common structural elements for such vehicles is the rectangular plate

or panel, for which numerous stable static, buckling, and free-vibrational

analyses have been performed (reference 2). These advanced vehicles must

maintain their structural integrity not only during high staticly applied

mechanical and thermal loadings, but also in a variety of dynamic environ-

ments. In order to predict the dynamic stresses to which a structure will

be subjected, it is necessary to perform a dynamic response analysis in-

cluding the effects of damping properties as well as the various stiffnesses.

An example of this type of requirement is found in the Space Shuttle now

under NASA preliminary development (reference 3).

A composite material is defined as two or more materials joined to-

gether to form a nonhomogeneous material, which is used in constructing

structures. Although such a material is nonhomogeneous on a micro scale, it

behaves tnacroscopically as if it were a homogeneous, anisotropic material.

An anisotropic material is one which exhibits different properties when

tested at different directional orientations within the body. For example,

a single layer of composite material containing unidirectionally oriented

fibers (hereafter referred to as a unidirectional composite) has consider-

ably greater stiffness and strength in the direction of the fibers than it

does in a direction transverse to the fibers (see figure 1). This aniso-

tropic aspect is one of several which makes structural analyses for composite-

material structures more complicated (reference 4) than those for ordinary

isotropic materials, such as aluminum alloys or many unfilled plastics.

A single layer of unidirectional composite has certain orthogonal

axes of material symmetry and thus is said to be orthotropic. and behaves

in considerably simpler fashion than a general anisotropic material. If

the material is thin it is called plane orthotropic. However, for purposes of

obtaining a more efficient design, it is often advantageous to place dif-

ferent layers or plies at different orientations. For the case of a thin

plate, this means that we must consider it as a plane anisotropic material.

This treatment is intermediate between the complicated general anisotropic

case and the much simpler plane orthotropic case.

A laminate consists of two or more layers integrally joined together.

It is said to he laminated symmetrically if all of the layers above and be-

low the mid plane of the laminate have the same dimensions, properties, and

(orientation)(if the layers are orthotropic); see figure 2. A laminate is

said to be balanced if all of the layers oriented at -1-9 are balanced by an

equal number of identical layers at an orientation of -9; see figure 3.

If a laminate is not symmetrically laminated, coupling occurs between in-

plane (either normal or shear) stress on one hand and either bending or

twisting deformation on the other hand. In such a case as a laminate

consisting of a metallic substrate and a few layers of overlaying filamentary

'composite material, considerable bending-stretching coupling can occur and

thus, it is necessary to consider not only the in-plane and bending stiff-

nesses but also the coupling stiffnesses which couple together the other

two effects (reference 4). Obviously, this is considerably more complicated

to analyze than a simple single layer.

Unfortunately, it appears that no one has yet succeeded in devising

'a lamination scheme that is both symmetrical and balanced. However, in the

•'special, yet practical, case of multiple identical layers oriented alter-

'nately at +9 and -9, as the number of layers is increased, the bending-

coupling effect diminishes (reference 5). For more than ten such layers,

the bending-stretching coupling may be neglected for most engineering pur-

poses and, thus, the laminate may be treated macroscopically as if it were

a single-layer plate.

It has long been recognized that, due to the relatively low shear

stiffnesses of composite materials in planes normal to the laminating plane,

the thickness-shear* deformations must be included in the analysis, even

when the plate is relatively thin (references 6-8), in order to achieve

reasonably good predictions of laminate flexural behavior. Although

several existing laminated plate theories include thickness-shear flexibility,

all of them require an ad hoc assumption of the required shear correction

factor. In this report, two different, relatively simple procedures are

fSometimes referred to as "transverse shear", especially in the case

of beams. The terminology used here follows that established by Yu for sand-

wich plates (reference 9). Here the term, transverse, is reserved for the

in-plane direction which is normal to the longitudinal direction.

3

presented to enable rational prediction of the appropriate composite shear

correction factor (K) . The frequencies calculated using these values for

K in shear-flexible laminated plate vibrational analysis give good agree-

ment with the exact three-dimensional elasticity solution, which is com-

putationally much more complicated.

The use of high-damping polymeric materials in the form of a thin

layer or tape has come into widespread use as a structural damper to reduce

the vibrational response of aircraft panels, especially in high-noise regions

such as in the vicinity of jet engines. When the polymeric material is

added on either one side or both sides, it is known as an unconstrained

damping layer; when the polymeric material is placed between two or more

layers, it is called a constrained damping layer (or layers). Appropriate

analyses and design procedures have been developed for including either type

of damping layer, assuming all layers (metal and polymer) are isotropic

(references 10-12). However, so far as known, no detailed solutions have

been published on vibration of laminated composite-material plates which in-

cluded material damping. Such an analysis is presented in this report and

the results are compared with experimental data reported recently by Clary

(reference 13).

1.2 A Brief Survey of Selected Vibrational

Analyses of Laminated Plates

Apparently the first vibrational analysis was carried out by Pister

(reference 14) for a thin plate arbitrarily laminated of isotropic layers.

In this case, the net effect of the bending-stretching coupling resulted in

a reduced flexural stiffness.

Stavsky (reference 15) formulated a coupled bending-stretching

dynamic theory for thin plates laminated of composite-material layers,

but he did not present any numerical results. Apparently the first pub-

lished results of the vibrational analysis of such plates is due to Ashton

and Waddoups (reference 16), who used the Rayleigh-Ritz method to analyze

rectangular plates. These results compared reasonably well with experi-

mental results for the completely free and cantilever cases. A similar

analytical and experimental study, but involving simply supported and free

boundary conditions, was carried out by Hikami (reference 17). Additional

analysis of the free-edge case was carried out by Ashton (reference 18).

For simply supported plates, Whitney and Leissa (references 19,20)

presented closed-form solutions for the natural frequencies in the case

of cross-ply and angle-ply lamination schemes. As would be expected, their

results showed a strong effect of bending-stretching coupling in lowering

the natural frequencies.

The case of clamped boundary conditions is more complicated analyti-

cally, but more representative of practical aerospace structures. Rayleigh-

Ritz and experimental investigations of such structures were carried out

independently by Ashton and Anderson (reference 21) and by Bert and May-

berry (reference 22).

The first more accurate vibrational analysis of laminated plates in-

cluding thickness-shear flexibility was made by Ambartsumyan; see reference

23. He assumed an arbitrary distribution of thickness-shear stresses through

the thickness. However, in carrying out his actual calculations, Ambart-

sumyan assumed a simple parabolic distribution. It can be shown by a

simple mechanics-of-materials analysis (Jourawski shear theory; see Section

5

Ill) that the thickness-shear stress distribution must be discontinuous

from layer to layer; thus, the simple parabolic distribution does not hold.

Ambartsumyan did not give any numerical results for vibration of laminated

plates; however, Whitney (reference 24) did so, using Ambartsumyan's basic

theory.

Using another approach, Yang et al (reference 25) entended the Mindlin

homogeneous, isotropic, dynamic plate analysis (reference 26) to the laminated

anisotropic case. They assumed a thickness-shear angle which is independent

of the thickness coordinate (z) and then integrated the stress equations of

motion to obtain the governing partial differential equations. After

integration, they introduced a thickness-shear coefficient in an ad hoc

fashion to correlate the predicted frequencies with known results.

Also Yang et al introduced the coupling inertial effect (present

only in the case of plates laminated unsymmetrically with respect to mass

distribution), as well as the familiar translational and rotatory inertia

effects present in homogeneous (or mass-symmetrically laminated) plates.

The inclusion of these higher-order inertial effects is consistent with the

inclusion of thickness-shear flexibility.

The analysis presented in this report is an improvement over both

the Ambartsumyan and Yang et al analyses, in that it presents simple rational

means for calculating the shear coefficient, rather than assuming it a priori.

An alternative to considering shear deformation per se is to make a

microlaminar analysis, such as considered by Biot (reference 27) and

Bolotin (reference 28). However, this approach has not been used very ex-

tensively so far.

Another approximate approach is to use the Voigt and Reuss models to

6

determine the properties of an equivalent homogeneous, anisotropic, shear-

flexible plate. This method was originated independently by Postma (refer-

ence 29), White and Angona (reference 30), and Rytov (reference 31) to

investigate wave propagation in a continuum consisting of alternating layers

of stiff and flexible isotropic materials. This concept was applied re-

cently to plates with experimental verification for the special case of a

beam, by Achenbach and Zerbe (reference 32). A new analysis, extending the

Postma approach to the more general case of a laminate consisting of alter-

nating orthotropic layers, is presented in Appendix F.

All of the analyses mentioned above are approximate formulations in

this sense: interlaminar compatibility is impossible unless both of the

in-plane Poisson's ratios are identical in all of the layers. The reason

for this is that, in a plate, one can have discontinuities in the strain

component in a given direction in the plane, due to the Poisson contraction

caused by a stress resultant or a stress couple acting in the perpendicular

direction in the plane. This deficiency can be removed by using the ap-

proach introduced recently by Hsu and Wang (reference 33) and Wang (refer-

ence 34) for laminated shells. Another technique is to apply the nonhomo-

geneous three-dimensional elasticity approach, such as used recently by

Srinivas et al (references 35-37) for a special case of simply supported

edges. Still another method is to use finite elements in the thickness

direction, as introduced recently by Tso et al (reference 38). Unfortunately,

all of the more accurate analyses mentioned in this paragraph are quite

complicated computationally and thus are not amendable to engineering

analyses of practical structural elements. Furthermore, the work of refer-

ence 37 showed that for structurally reasonable values of the following

modal parameter, the Mindlin-type theory (such as extended here) is

sufficiently accurate for determination of natural frequencies, but not for

determination of the associated stress distribution.

There are numerous analyses in the literature on vibration of damped

plates with isotropic layers; also there are a few vibrational analyses

of single-layer, anisotropic plates and a few quasi-static (creep) analyses,

of laminated, anisotropic plates. However, vibrational analyses of laminated,

anisotropic plates are quite limited. Dong (reference 39) indicated the

solution for the dynamic response of a simply-supported rectangular plate

arbitrarily laminated of orthotropic, viscoelastic plies modeled as a

standard linear solid.

SECTION II

FORMULATION OF THE THEORY OF LAMINATED, SHEAR-FLEXIBLE PLATES

In this section is presented a theoretical analysis of sinusoidally

forced vibration of laminated, anisotropic plates including bending-

stretching coupling, thickness-shear, all three types of inertia effects,

and material damping. First the assumptions, on which the analysis is

based, are stated explicitly. The general analysis is applicable to plates

with any combination of natural boundary conditions at their edges. The--;

analysis begins with the anisotropic stress-strain relations for a single

layer and proceeds through the stiffness and damping constitutive relations,

formulation of the various types of energy and work terms, and culminates

in the formulation of an eigenvalue problem by application of the extended

Rayleigh-Ritz method.

2.1 Hypotheses

The following assumptions are made in the analysis presented here:

HI. All displacements are assumed to be sufficiently small so that

the linear strain-displacement relations are sufficiently accurate.

H2. The layers which make up the plate are linearly elastic and

may be isotropic or orthotropic with any arbitrary orientation in the

plane of the plate.

H3. The layers are sufficiently thin that thickness-normal-stress

effects may be neglected, i.e. the layers are assumed to have finite

stiffnesses which resist membrane, bending, and thickness shearing

stresses.

H4. The layers are assumed to be bonded together perfectly.

H5. The plate is assumed to have all components of translational,

translatiohal-rotatory coupling, and rotatory inertia.

H6. All material damping effects are assumed to be small. They

are incorporated by using stiffnesses which are complex rather than real

(see Appendix B); the complex-stiffness array is assumed to be symmetric

(see Appendix I). All other thermal effects are neglected.

H7. All initial-stress effects are neglected.

H8. All interactions with a surrounding fluid can be either

neglected or considered to be included in the values used for the material-

damping coefficients.

H9. The excitation consists of a uniformly distributed normal

pressure loading, sinusoidal with respect to time.

2.2 Kinematics

The displacement field is assumed to be (hypothesis H3) :

u (x,y,z,t) = u (x,y,t) + zy (x,y,t)

v (x,y,z,t) » VQ (x,y,t) + z\t (x,y,t) (1)

w (x,y,z,t) = WQ (x.y.t)

where u,v,w are the displacement components in the x,y,z directions (see

figure 4); u ,v ,w are the displacement components at the middle surface

10

of the multi-layer plate; ijj and i|t are the weighted middle-surface rotationsx y

in the respective xz and yz planes; and t is time.

Within the framework of hypothesis HI, the total engineering strains

are given by the following in-plane strain-displacement relations:

(no sum)

where

e=u ; e = v ; e = v + u (3)xx o,x *yy o,y xy o,x o,y

H = i|i ; x = ii/ ; K ' = I | J + \ ! J (4)xx x,x yy y»y xy y,x x,y

Also the following thickness-shear strain-displacement relations

hold:

e = w + \ | i ; e = w + i t / .(5)xz o,x *x yz o,y Ty

where a subscript comma denotes partial differentiation with respect to

the variable following the comma, i.e. u ? ^u /£x.

2.3 Stiffness Constitutive Relations

In line with hypothesis H2, the following stress-strain relations

are assumed to hold for each individual layer of which the plate is com-

prised:

11

'°lk)1

yy

a(k>yz

xz

a(k>I, *y J

> =

"<« Q« o o „<»-

o y o o oL£ £ £ 4_ O

0 0 Q.(k) Q.(k) 044 45

0 0 Q<k> Q<k> 0

Q«0 (k) (k)_^16 W26 0 U 66 _

<

, \

exx}

e(k)

yy

eyz

exz

e(k)

l e x y J

(6)

(k") (k") (k) (k)where O , a are the in-plane normal stresses; a , a ' are thexx yy xz yz

(k)thickness-shear stresses; O is the in-plane shear stress; the Q

are the reduced stiffness coefficients which are applicable to a thin

layer (see Appendix A); superscript (k) denotes a typical layer k, where

k = l,2,3...,n ; and n is the total number of layers of which the plate

is comprised.

It is noted that it is more consistent mathematically to write

the stress-strain relations in either matrix form as

(7)

or in tensor notation as

(k) (k)(i,j=x,y,z) . (8)

However, here a mixed notation is used for engineering convenience:

double lettered subscripts (xx,yy,yz,xz,xy) following classical

elasticity theory notation for stresses and strains, and double numbered

subscripts (i,j=l,2,4,5,6) to reduce the number of subscripts used on

the stiffness coefficients.12

As is conventional in plate and shell theory, it is convenient to

introduce generalized forces which are applicable to the whole laminate,

rather than only a specific distance from the plate middle surface.

(k)The stress components, o. . , are functions of x,y,z; therefore, integrat-

ing them through the thickness yields the following generalized forces,

which are functions of x,y only:

h/2,_,N ,N ,Q ,Q| B f {a(k),o(k),o(k),o(k),o(k)) dz

xx' yy' xy'xx'xyJ .) ,_ I xx ' yy ' xy ' xz ' yz J

= 7 J {a(k),o(k),a(k>a(k),a(k)ldz (9)L J I xx yy xy' xz yz fk=l Zk-l

{M ,M ,M ], [{o(k), a(k),a(k)}zdzI xx yy xyJ J h/9 xx ^ x^

I xx yy xyk=l k-1

where h =? total plate thickness, the quantity (zk~z. ,) is the thickness

of an individual layer (see figure 5), N.. ^ membrane stress resultants

(force per unit length), Q. ^ thickness-shear stress resultants (force

per unit length), and M.. are the stress couples (moment per unit length)

Inserting the stress-strain relations, given by equations (6) in-

to equations (9) and (10), one obtains the following constitutive re-

lations for the composite:

13

x \NXX

Nyy

Nxy

MXX

MyyMxy

V> ,

( _

" All A12 A16 I Bll B12 B16' ° °l i

A12 A22 A26 i B12 B22 B26 j ° °

A16 A26 A66 : B16 B26 B66 j ° °

11 12 16 ' 11 12 16 1I

IB12 B22 B26 j °12 °22 D26 j ° °

I

B16 B26 B66 _] °16 °26 °66 i ° °_ _ _.

0 0 0 ' 0 0 0 ,F.. F . _. " 44 45

o o o i o o o (F45 F55

/ NO

0eyy0

_€_xy

KXX

Kyy

Kxy

eyz

k e

xz

(11)

where the respective stretching, bending-stretching coupling, and

bending stiffnesses of the plate are defined as follows:

12(

h/2dz (12)

and the thickness-shear stiffnesses of the plate are as follows:

rh/2 (MFij * Kij J. ,?i1 dz <l»^»5> (13)

where K.. = composite shear coefficient, introduced to account for the

thickness-shear strain variation through the thickness. Section III

presents several approximate analyses to predict K.. analytically.

The A.., B.., and D. . submatrices appearing in equation (11) are

present in the classical Kirchhoff-type theory of laminated plates (see

refs. 4,5,15-22). In the case of an orthotropic plate all of the terms

with subscripts 16 and 26, called the cross-elasticity or shear-coupling

terms, vanish. Furthermore, when the layers are all isotropic materials,

14

only two of each set of the terms with subscripts 11,12,22, and 66 are

independent.

If the plate is either homogeneous (i.e. single layer) or laminated

symmetrically about the plate middle surface, the bend ing-stretching cou-

pling stiffness submatrix B. . vanishes. Then the only remaining terms are

the A., and 0.. submatrices, which are present in classical, homogeneous

thin-plate theory.

The thickness-shear stiffness coefficients F. . account for the pre-

sence of thickness-shear strains, in a manner which can be considered to

be B generalization of that used by Mindlin (ref. 26) for homogeneous,

isotropic plates. To reduce the present theory to the classical Kirchhoff-

type plate theory, the thickness-shear strains would be omitted; thus,

from equations (5), one would obtain:

*x = ' Wo,x ; *y = - Wo,y

Furthermore, one would delete the thickness-shear strains, e and e ,

from equations (11) and the thickness-shear stress resultants, Q and Q ,x y

would be computed from equilibrium considerations only.

2.4 Strain Energy

The differential of the strain-energy density (strain energy per

unit volume) is given by:

«= o(k) de(k) + 0(k) de(k) + a(k) de

(k)

v xx xx yy yy xy xy

15

Integration of equation (15) yields:

U<k)=(l/2) [u(k) e(k) + o(k) e

(k) + o(k) e(k>v xx xx yy yy xy xy

. (k) (k) (k) (k) .°yz eyz xz exz ] (16)

The strain energy per unit of plate area (U ) is the integral ofA

GOU over the total thickness of the plate:v

h/2 n ZkU = [ U ( k > d z = 7 f U ( k ) dz (17)

A J -h /2 V /•. J«. . Vk=l k-1

Substituting equations (16) , (6), and (2) into equation (17) , per-

forming the integration, and using equations (12) and (13), one obtains

the following expression for the strain energy per unit area:

(1/2)

26 xy 66 « 112A « + A <* + 2B

+ 2 B10(e° K + e° H ) + 2 B_, e° K12 xx yy yy xx 22 yy yy

+ 2 B, , (e° H + e° K ) + 2B0 ,( e° K + e° K )16 xx xy xy xx' 26 yy xy fcxy yy

ty f*

+ 2 B,, e H + D * + 2 D K K + D00 K66 xy xy 11 xx 12 xx yy 22 yy

2 2+ 2 D16 \x Kxy + 2 °26 Kyy \y + °66 Hyy + F44 eyz

+ 2 F45 eyz exz + F55 exz 3

16

2.5 Damping Coefficients and Dissipative Energy

For a material with Ktmball-Lovell structural damping (see Appendix

B), the stress-strain rate relation for sinusoidal motion at a circular

frequency uu can be expressed as follows:

o = (b/iu) e (19)

where b is a material constant and e is the strain rate.

The strain is given by

1 f H4.

(20)

where i = ./-I.

Thus,

e = iue (21)

Substituting equation (21) into equation (19), one obtains:

d = Qe (22)

where

Q = ib (23)

Generalizing equation (23) to the entire array of stresses and

strains in layer "k", in contracted notation analogous to equation (7), we

* (k)obtain the following expression, where Q is symmetric (hypothesis H6) :

17

Equation (24) is the same as equation (7), except that here the

presence of the hat symbols (*) denotes damping quantities rather

than elastic quantities.

The energy dissipated per unit of plate area, due to damping,

is denoted by the symbol D.. The expression for it in terms of theA

midplane strains (e..) and the curvatures (H .) is the same as

equation (18), except for the presence of the hat symbols over all

of the A , B.., Dj.» and F.. quantities, where

(25).<*">,,

where gi> are loss tangents (see Appendix B).

2.6 Kinetic Energy

The differential kinetic energy of an elemental volume (dx by dy

by dz) is given by:

(p(k)/2) (u2 + v2 + w2) dx dy dz

(k)where p is the density at the point (x,y,z) and u,v,w are the velocity

components in the x,y,z directions respectively.

Now the kinetic energy per unit of plate area is obtained from the

differential quantity given above by dividing by dx dy and integrating

over the entire thickness of the plate, as follows:

18

(p(k)/2Xu2 + v2 + w2)TA • (P V2Xu + v + w ) dz (26)A J-h/2

Substituting the kinematic relations, equations (1), into equation

(26) and performing the integration, assuming that the density is uni-

form through the thickness of each individual layer, one arrives at the

following expression:

T. = (m /2)(u2 + v2 + w2) + m. (u ty + v ijf )A o o o o 1 o x o T y

+ (m 12) (\2 + ft (27)£• x y

where m ,m , and m are respectively the mass per unit of plate area,

first moment of mass per unit area (coupling inertia), and second

moment of mass per unit area (mass moment of inertia) , defined as

follows :

2k

k=l zk-l

dz <28)

Only the coefficient m appears in classical Kirchhoff theory for

the dynamics of thin, homogeneous plates. The Mindlin dynamic plate

theory of homogeneous plates (ref. 26) contains both m and m_ , while the

dynamic theory originated by Yang et al (ref. 25) for laminated plates

contains m , m, , and m. .o 1 i.

2.7 Work Done by External Forces

19

The only external force considered here is a uniformly distributed

normal pressure which has a sinusoidal wave form in time. Thus, it can

be written in complex variable notation as follows:

q(x,y,t) = q eilljt (29)

where q ~ amplitude of the normal pressure.

The following expression for the total work done may be derived

easily from the principle of virtual work:

W = I I q (x,y,t) w (x,y) dx dy (30)o o

2.8 Application of the Extended Rayleigh-Ritz Method

Since the present problem is one of steady-state harmonic ex-

citation denoted in complex-variable exponential forms, the displacements

and rotations are proportional to e also. It is noted that the phase

angle between the response and the excitation is taken care of by the

imaginary components of these quantities. Thus, the time dependence

cancels out in all of the energy terms which appear in Lagrange's equation.

Therefore, it is necessary to consider only the amplitudes of the re-

spective energy and work terms. Then, as shown in detail in Appendix

C, the amplitude of the Lagrangian energy difference can be expressed

as follows:

L~ = (T + W) - (U + D) (31)

20

where D.f.U.W are the amplitudes of the dissipative, kinetic, and strain

energies and of the work done by the external forces, respectively.

The strain and damping energy terms can be combined by introducing

complex stif fnessses , as discussed in Appendix B. Making this sub-

stitution and integrating over the plate area, we obtain the following:

a b

\ I I {A-, u2 + 2A.-1i v + A,0v2 + 2(A,,:U +A_,v ) (v +u )JQ J I 11 uo,x 12uo,x o,y 22 o,y x 16 0,x 26 o,/ v o,x o,y

•^^(v +" )2 + 2B. .U .ty + 2B,,(u' ^ +v ^ )+2B0 'v 'if66 o,x o,y 11 O , X T X , X 12 o ,x T y ,y o ,y r x ,x 22 o .y^y.y

+2B1,[ui (^ +$ )+(v +u )"$ 1 + 2B0,[v ("$ -Hj )16L o ,x v y y ,x vx,y v o,x o,y Yx,x 26 o,y y,x Y x,y

+ (v -hi )f ] + 2B,,('v +u )(^ +7 ) + 6 '\[(2

o,x o , y / Y y , y J 66V o,x o , y / v y y , x *x,y H Y x , x

,,16yx,x y,x ''x.y'

7

dx dy (32)

where the superscript ('-) denotes that the quantity is an amplitude, and

V(33)

The sum of the amplitudes of the kinetic energy and the work done

by external forces can be expressed as follows:

21

,b

\> x"o ' "o ' "o' ' -1"r."o1'xT-W = (oj2/2) f f [m (u2 + v2 + w2) + 2m, (u f +

J J u Y

o o

~2 ~2 fa fk ~ ~+ nu (i|f + i|» )] dx dy +1 q \* dx dy (34)"2 vvx T V

o o

To apply the extended Rayleigh-Ritz method, the assumed functions

for the amplitudes of the displacements and rotations are given the

following general form:

M N

, u $ (o/)fo /_. l-i mn urn unm=l n=l

M N

v / ) V $ (o)*L L, mn vmo , mn vm vn

tn=l n=l

wo

ft f) > w,/ W $ (a)* (B) (35)

c- mn wm wnm=l n=l

M N,

/ } Y *. (a) $ (B)

m=l n=l

M N

y / « *. (cy)$, (B)/_. c.; xmn \jixm •'"—m=l n=l

The modal coefficients U ,V ,W ,Y ,y are the undeterminedmn mn mn ymn xrnn

parameters, the $'s are assumed modal functions, a ~ x/a, p :- y/b.

Substituting equations (32), (34), and (35) into equation (31)

for the Lagrangian energy-difference amplitude (L), one obtains the

result presented in Appendix Dl.

Hamilton's principle can be stated mathematically as follows:

22

6 | L dt = 0 (36)"t.

To achieve as close of an approximation as possible to equation

(36), the Lagrangian function L is minimized by setting its partial

derivatives with respect to the modal coefficients respectively equal

to zero, i.e.

(37)

=0 ; k = 1,2,..., M ; f = 1,2,..., N

Equations (37) represent a set of M x N nonhomogeneous, linear algebraic

equations.

2.9 Reduction to Matrix Form

For computational convenience, it is desirable to express the set

of equations (37) in matrix form as follows:

5 J - "2[M] (O = M (38)

where [S] --• complex stiffness matrix, [M] ~ mass matrix, and '.£ | and

| f I are column matrices representing the generalized -displacements and

generalized forces, respectively, i.e.

23

mn

Vmn

Wmn

'ymn

xmn

0

0

'q

o

o

(39)

Equation (38) can be written in explicit complex form as follows:

mn mn ran (40)

where superscripts (R) and (I) denote the real and imaginary parts of

the complex quanti t ies appearing in equation (38).

Equation (40) can be solved for the response matrix, partitioned

into real and imaginary parts, as follows:

-s(I)

s(R>- «,VR>

-1f(R)l

(41)

The modal coefficients are placed in the inverse matrix in equation

(41). For the specific numerical case treated M=N=2, i.e. m,n=l,2. Thus,

the complete matrix is of order 40 x 40 with each submatrix being of

order 2 x 2 . Thus, the problem has been reduced to a standard algebraic

eigenvalue problem which can be solved by an available computer suboutline

for the IBM 360 Series bQ digital computer. Complete computer program

documentation is presented in Appendix J.

24

SECTION III

DERIVATION OF THICKNESS-SHEAR FACTORS FOR LAMINATES

In this section are presented two entirely different approaches

for calculating the thickness-shear factors for a laminate. The first

approach is to extend the Jourawski static theory of shear-flexible

beams (reference 40), as presented in elementary mechanics-of-materials

textbooks, to a laminated beam. The other approach is to extend, to

the laminate case, Mind 1in's method (ref. 26) of matching the pure

thickness-shear-mode frequencies predicted by two-dimensional dynamic

elasticity and by Timoshenko one-dimensional, shear-flexible beam theory

(references 41, 42).

In the case of isotropic plates, there is only one independent

thickness-shear factor (K) , since K 5=0 and K «K^=K. The static

approach mentioned above yields a value of K = 0.833 (reference 43),

while Mindlin's dynamic approach results in a value of 0.822 for K.

Srinivas et al. (ref. 35) showed that use of either of these values for

K in Mindlin's plate theory results in a very close approximation to

the lower natural frequencies computed by exact, dynamic, three-dimensional

theory of elasticity for rather thick, homogeneous isotropic rectangular

plates simply supported on all edges.

In the case of orthotropic plates, there are two independent thick-

ness-shear factors (K,, and K,.,.) , since K, ,.=0 and K_,^K,,. In the case

of a plane anisotropic plate, such as one consisting of a unidirectional

25

composite material with its major material-symmetry axis oriented at an

acute angle (0) with its edges, there are three independent, non-zero

K... However, for this case, Appendix A presents transformations from

which the three F.., proportional to K. . and defined in equation (13),

can be calculated from the following data: F and F for the orthotropic

case (0=0 ) and the value of 0 in the anisotropic case. Thus, the general

problem of determining K . is reduced to one of calculating K, , and K,.,.

for the orthotropic case.

To calculate KSE. for an orthotropic laminate by either of the two

approaches mentioned above, one considers a beam oriented in the x

(k)* (k)direction and laminated of layers having properties E.. . and C_5 . To

calculate K44, x - y, E- E , and

To provide a check for the results, the fundamental eigenvalues

for free vibration calculated by laminated, shear-flexible plate theory

(Section II), using these values of K. ., are compared with the exact

laminated elasticity theory values given by Srinivas et al. (ref. 35).

3.1 Static Approach

To calculate the horizontal shear force per unit width, AF, acting

on a cross section, figures 6 and 7 are used. For consistency plate notation

is used, even though the theory is only one dimensional.

The bending stress in typical layer "k", at a distance z from the

midplane of the laminate, is calculated as follows:

(k) = E(k)K z (42)

XX 11 XX

* (k) (k)For thin plates as treated in this report, E|. -• Q),, where

(k)_ E<k), Q _v(k) <kKll = Ell ' (1 V12 V21 )m 26

(k)where * = longitudinal bending curvature and E.1 = longitudinal Young's

XX i. 1.

modulus of layer "k".

The longitudinal stress couple (bending moment per unit width) is

defined as follows:

V fzk mMxx = L\ °xxzdz

k=1

The longitudinal curvature can be expressed in terms of M asXX

follows:

K = M /Dnl (44)XX XX 11

where D.j ^ longitudinal flexural rigidity.

From equations (42) and (44) , the bending stresses acting on the

left (x=x ) and right (x = x^Ax) sides of the elements are:

Z/Dll)Mxx 5

(45)

Since both of these bending stress distributions act on identical

cross-sectional areas, the horizontal shear force per unit width, which

acts on the element, is given by:

AF = [o (x.+Ax)-0 (x.)] dA (46)JA xx i xx i

where A --- area shown in figure 3 .o

27

Combining equations (45) and (46), one obtains:

AF = (AM /D )Y(z) (47)XX JL J.

where

Y(z) = E(k)z dA= f EJA

The force per unit width, AF, must equilibrate the horizontal

(k)shear stress, a , acting on the bottom face of the element shown in

figure 7. Thus, we have:

AF = a(k) Ax (48)xz

Hooke's law in shear for layer "k" is

a(k) - Ce (49)xz 55 xz

( k) ( k)where C and e are the modulus and strain corresponding to longi-55 xz

tudinal thickness-shear action in layer "k".

Substituting equation (49) into equation (48) , one obtains the

following result:

AF = C 'e 'Ax (50)

The following expression for the longitudinal shear strain at

a distance z is obtained by equating the right-hand sides of equation

(47) and (50) :

28

exz>(x'z)

where Q is the thickness-shear stress resultant (force per unit width),A

which is related to M by static equilibrium as follows:A A

Qx - AMxxMx (52)

The shear strain energy for a laminated, rectangular-cross-section

beam, shown in figure 9, is:

Jc-Le-TdA (53)

The shear strain energy associated with an equivalent uniform,

longitudinal thickness-shear strain in a laminated, rectangular-cross-

section beam of cross-sectional area A is:

where K is the longitudinal thickness-shear factor and e' is weightedJj X Z

according to:

n k n

xz U J xz xz

Vi k'1 zk-i

Equating the right-hand sides of equations (53) and (54) yields an

equation; then substituting equations (49) and (51) into that equation,

one arrives at the following explicit expression for the longitudinal

29

thickness-shear factor

J Y(z) dz]1

k=1 z

k=l Zk-l k=l Zk-l

Equation (56) is a general expression for the static, longitudinal

thickness-shear factor for an arbitrarily laminated beam. It is a

relatively simple algebraic expression which depends upon only the

longitudinal Young's and thickness-shear moduli of the individual layers

(k) (k)(E / and C^ ) and the lamination geometry. Numerical results are

presented in later examples.

3.2 Dynamic Approach

Due to the inherent mathematical form of the equations of dynamic

elasticity theory for a multi-material (multi-layer) medium, it is not

feasible to present a general solution for the thickness-shear factor

obtained by using the dynamic approach. Even in the case of a specific

class of laminate, such as the three-layer, symmetrically laminated one,

it is not possible to obtain an explicit expression for the thickness-

shear factor. In fact, the complexity of the dynamic case, which in-

volves the dynamic elasticity-theory analysis of a shear-flexible

laminated beam, approaches that of the shear-flexible laminated plate and

thus negates much of the advantage of using the thickness-shear factor

30

approach to laminated, shear-flexible plate dynamics. However, in order

to illustrate the dynamic approach and to provide a numerical comparison

with the static approach and with the exact results of Srinivas et al

(ref. 35), an analysis for the symmetrical three-layer case is presented

in Appendix E.

31

SECTION IV

MODAL FUNCTIONS USED FOR VARIOUS

PLATE BOUNDARY CONDITIONS

In applying the extended Rayleigh-Ritz method, the approximate

modal shapes assumed must satisfy the kinematic boundary conditions.

However, to improve convergence, it is desirable to satisfy the force-

type boundary conditions also. For a rectangular plate, the three cases

of boundary conditions most commonly encountered in practice are discussed

in Sections 4.1-4.3.

It should be noted tha C , C , Z , Z are characteristic parametersm n m n

tabulated in reference 44. Also, five boundary conditions per edge need

to be prescribed rather than four as in classical theory.

4.1 Simply Supported on All Edges

The boundary conditions considered here are simply-supported edges

in the sense that

N = M = v = w = i l i = 0 a t x = 0 , a (o/=0,l)XX XX O O y

<5 7>N = M = u = w = \ j i = 0 a t y = 0 , b (0=0,1)

yy yy O O YX J » v H i /

As was pointed out by Wang (reference 45), it is impossible for a

separable-form deflection function to satisfy the above boundary conditions

for the case of a plate of anisotropic material (Q., and Q~, ^ 0). However,lo £o

the following modal functions permit eqs. (35) to satisfy eq. (57) exactly

32

in the orthotropic case, but only approximately in the anisotropic case:

(58)

= $ = cos mrrrY ; $ = $ = $. = sin timo/urn \Jixm vm \fln \|iym

$ = $ = cos nrr8 ; f = $ = $. = sin nrrBvn tyyn K un wn \)/xn H

For the simply supported case, we substitute equations (58) into

equations (D-l through D-6). The evaluations of the integral forms are

presented in Appendix G.

4.2 Fully Clamped on All Edges

The boundary conditions for a fully clamped laminated plate are as

follows:

u =v =0 a t x = 0 , a and y = 0,b

w = w = i l i = 0 a t x = 0,a (59)o o,x Ty

w = w = T i = O a t y = 0,bo o,y Yx J

The assumed modal functions selected to permit equations (35) to

satisfy equations (59) are as follows:

= 4 > = $ = 4 = s i n 2mrro;um vm \jixm ~i|iytn

$ = $ = $ = $ , = s i n 2nTr8un vn tyxn \)iyn

}> = cosh Z a - cos Z a - C (sinh Z o - sin Z a)wm m*^ m m m m

$ = cosh Z P - cos Z 0 - C (sinh Z p - sin Z p)wn n n n n n

(60)

33

For the fully clamped case, we substitute equations (60) into

equations (Dl through D6). The evaluations of the integral forms are

presented in Appendix G.

4.3 Free on All Edges

The boundary conditions appropriate for a laminated plate free on

all edges can be expressed mathematically as follows:

N =M =0 a t x = 0,a and y = 0,bxy xy

N = Q = M = 0 at x = 0,a (61)XX X XX

N = Q = M =0 at y = 0,byy y yy

The assumed modal functions selected to permit equations (35) to

satisfy equations (61) are as follows:

fc = $ = $, = $, =1- cos 2mmurn vm \jixm \|iym

= $ = 4 > , = $ =1- cos 2nna (62)un vn tyxn \jiyn

$ = cos mno ; $ = cos nrrSwm wn

For the free edge case, we substitute equations (62) into equations

(Dl through D6). The evaluation of the resulting integral forms are

presented in Appendix G.

34

SECTION V

NUMERICAL RESULTS AND COMPARISON WITH

RESULTS OF OTHER INVESTIGATORS

In this section a comparison is made between the numerical results ob-

tained in this investigation and those obtained by other investigators.

5.1 Thickness-Shear Factors for Laminates

Two example problems are analyzed and, where possible, results of

Example 1 are compared with solutions obtained from other sources. The

results of Example 2 are presented for use in design.

Example 1: Three-layer, symmetric. isotropic_laminate. - The coordinate

system is shown in figure 10. All geometrical and material property ratios

correspond to the data of ref. 35 given as follows:

z-/z, = h /fh +2h 1 = 0.8 , E,, /E,, — 15,2 1 1 1 1 1

p(2)=l , and v(1) = v(2) = 0.3

Assuming only the x-direction is considered in the static and dynamic

approaches which were developed in Section III,then the following results

are obtained: (I) static case - the result obtained from equation (56)

can be expressed as K,.c=0.651, (II) dynamic case - the result obtained by

equating eqs. (E-13) and (E-27) is K55=0.350.

35

When the three-layer, laminate thickness parameter is chosen to be

Z2^zl =1» C^e analysis given in Section III can be reduced to a single-

layer homogeneous, isotropic material. Thus, using the data E /E^ -

C55)/C55) = P ( 1 ) /P ( 2 ) = = 1 and v(1) = v (2) = 0.3, the static case gives

K,-c = 0.833 and dynamic case results in K ,. = 0.822. These results are

identical with the values of the static and the dynamic shear factors

obtained for single-layer plates by previous investigators (refs. 43 and

16).

Example 2: Mult ip le alternating layers of two materials. - The

geometrical and material property ratios are given as

' C55>/C55)

The laminates vary from two layers to nine layers. Since the static

case is a relatively simple algebraic expression which considers only

longitudinal Young's and thickness-shear moduli of the individual layers

(k) (k)(E^ and w,. )and the laminate geometry, for design purposes, eq. (56)

will be used. The results are shown in table 1 and figure 11.

5.2 Plate Simply Supported on All Edges

Here we consider only free vibration of plates made of composite

material having material-symmetry axes coinciding with the geometric

coordinates (plate edges) as shown in figure 12 . Neglecting energy

dissipation, the time integral of the difference between the potential and

kinetic energies attains a stationary value. The displacement and rotations

36

are proportional to e . The time dependence in the strain and kinetic

energies cancel each other, i.e. only the amplitudes of the strain energy

and kinetic energy need be considered. Thus, we use only the real part

of homogeneous eqs. (D1-D6) with proper boundary conditions, see eq.

(57) , to apply Example 3.

Example 3: Three-layer, symmetric . isotropic plate. - The elastic

coefficients are those of isotropic material:

, Q<k>

- Q<k) = Q<» - E<»/ [2[l+v<k>] } , Q<k>=0

Geometrical and material property ratios correspond to the data

of ref. 35, given as follows

z2izl = n - / L n - +Zh - J» 0.8, EjJ'/E^'- C^/C^-15,

=0.3

and the following dimensionless geometric parameter defined in ref. 35:

2 (k) 2 (k) 2 U r0-0002"2 for k=1

k l . ^ J 0.0128iT2 for k=2

When the thickness of three-ply laminates is chosen to be z2/Ei = 1»

it can be reduced to a single-layer material as a special case. Then the

material properties are as follows:

37

E < } > / E< 2 > = C < i > / C < ? = p < l > / p < 2 > = 1 ; v(1) = V(2) - 0.311 11 55 55

82

A FORTRAN IV program is employed to compute the lowest eigenvalues

of plates with simply supported edges. The two cases considered are:

(1) single-layer homogeneous, isotropic, and (2) three-ply symmetrical

construction. The results are shown as a solid line in figures 13 and

14. The static and dynamic shear factors calculated in examples 1 and

2 are also shown for comparison.

The static Jourawski shear theory and dynamic Timoskenko type

theory appear to give good results for K as evaluated by inserting in

laminated, shear flexible plate theory and comparing the lowest eigen-

values with those given in refs. 35 and 14.

5.3 Plate Free on All Edges

The problem considered here is forced vibration of a rectangular

plate made of an arbitrary number of composite-material layers each

having its major material-symmetry axis oriented at an arbitrary angle

with geometrical coordinates as shown in figure A-2.

Since the present problem is one of steady-state harmonic excitation

including material damping effects, the complete set of eqs. (D1-D6) with

proper boundary conditions, eqs. (61), must be used.

38

Example 4: Boron/epoxy plate with twenty-four parallel plies

oriented at an arbitrary angle. - The input-data material properties are

Young's and shear moduli (E.,, E00 , C. . , Ccc, C,,), major Poisson's ratio11 t-i- HH 33 DO

(v,2) , bending and twisting- stiffnesses (D,,, D2~, D.™. D,c), and their

corresponding loss tangents, as generated in ref. 46 from constituent-

material experimental properties. It is noticed that all of the above input

data are functions of frequency. Geometrical and material properties

correspond to the data of ref. 13, as follows:

length, a = 18.19 in ; width, b = 2.75 in.

o /thickness, h = 0.034 in. ; density, p = 0.000194 Ib-sec /in

angle of orientation, 9 = 0°, 10°, 30°, 45°, 60°, 90°

A FORTRAN IV program is employed to compute the eigenvectors of

a plate with all edges free. To obtain the resonant frequencies of the

first five modes, two different resonance criteria are applied. In the

peak-amplitude method, the system is excited harmonically and the amplitude

at a particular point (a = 0, (3 = 1) is measured over a range of fre-

quency. The amplitude of the response depends not only on the dynamic

characteristics of the system, but also on the amplitude of the force

applied to it. For a linear system the peak amplitude is taken as

maximum displacement per unit amplitude of force. Throughout this re-

port, this ratio is referred to as the response. A typical result of

response with varying frequency is shown in figure 15 for an angle of

orientation, 9 = 10 . The complete results are as tabulated in Table II.

In the modified Kennedy-Pancu method, the modal shapes, phase

relations between motions at various points, and coupling between the

39

various degrees of freedom are assumed to be unaffected by the presence

of a small amount of damping. Vectors are used for the analysis of the

results of forced vibration by making a polar plot (called the Argand

plane) of the displacement vector (amplitude and phase angle). In the

vicinity of resonance, the resulting curve would be an approximately

circular arc. Each point on the circle locus corresponds to a value of

frequency.

In the modified Kennedy-Pancu method, the resonant frequency is de-

fined to correspond to the point of the Argand-plot curve having maximum

change in arc length (As) per fixed change in frequency (Auj) . The

change in arc length AS can be determined approximately in analytical

fashion as the response amplitude (W/q) multiplied by the difference in

the phase angles corresponding to the two distinct frequencies (separated

by Alt)) , i.e.

As = (W/q) Acp

The parameter As/Au, is plotted versus excitation frequency in figure

16 for a specific angle of orientation, 9 = 10 .

As can be seen in the figure, the curves exhibits sharp spikes and

thus the Kennedy-Pancu resonant frequencies, i.e. the frequencies cor-

responding to the maximum points, can readily be found. The results obtained

in this fashion for all of the plates used by Clary are tabulated in Table II.

A discussion of experimental methods used to determine material

damping in composite materials is presented in Appendix H. Here the damping

ratios are calculated by using the modified Kennedy-Pancu method as expressed

in equation (B-69), Appendix B. It is noted that the damping ratio is the

40

ratio of material damping coefficient to critical material damping coef-

ficient. The results associated with each mode are tabulated completely

in Table II.

The nodal patterns of the first five modes are calculated from the

response at selected points on the surface of the plate. Twenty-five

points in the x direction and five points in the y direction are used.

The nodal patterns are shown in figures 17-22. The results appear to

be in good agreement with the data of ref. 13.

41

VI. CONCLUSIONS

The analyses in Sections II and IV were developed for the vibra-

tional problem of composite-material plates with thickness-shear flexibility

and material damping. The theory used in the analyses is that of Yang,

Norris, and Stavsky (ref. 25), which can be considered to be the laminated,

anisotropic version of Mindlin's dynamic plate theory.

To account for the effects of thickness-shear deformation, a shear

correction factor K was introduced. A variety of methods to arrive at

an appropriate shear factor have been proposed for homogeneous plates;

the most popular ones resulted in K = 0.833 for a static distribution

(ref. 44) and 0.822 for the dynamic case (ref. 26). Srinivas et al.

(ref. 35) showed that use of either of these values for K in Mindlin's

plate theory gives a very close approximation to the lower natural fre-

quencies computed by exact, dynamic, three-dimensional elasticity theory

for rather thick, homogeneous, isotropic rectangular plates simply sup-

ported on all edges.

Unfortunately to date no one has proposed a means of rational

calculation of the shear factor for a laminated plate. Srinivas et al.

made an exact, dynamic three-dimensional elasticity analysis of simply

supported laminated plates. However, their analysis is quite tedious

computationally and thus they have presented numerical results for only a

very limited number of cases.

42

In the present Investigation, both static (Jourauski shear theory)

and dynamic (Mindlin type analysis for pure thickness-shear motion)

approaches were used to derive a shear factor K for laminates.

An assessment of the accuracy of these theories was made by com-

paring the lowest eigenvalues calculated by the laminated, shear-flexible

plate theory with the laminated, three-dimensional exact values given

by Srivinvas et al. (ref. 35).

It has been found that the shear factor K for a laminate is not

the same value as that for a homogeneous, isotropic member. The numberical

examples indicated that the value of K depends on the layer properties

and the stacking sequence of the laminate.

Using peak-amplitude and modified Kennedy-Pancu methods, the first

five resonant frequencies were calculated for various laminated boron/

epoxy plates with all edges free. The resonant frequencies obtained by

the two techniques differed by only a very small amount, and were in good

agreement with the results obtained both experimentally and analytically

by Clary (ref. 13). Furthermore, the nodal patterns have been found to be

satisfactory or as good as the data given by Clary. Finally, the damping-

ratio results were in good agreement with the experimental ones obtained

by Clary. No comparison with analytical results for Imainated-plate

damping could be made, since they have not been available previously.

43

APPENDIX A

NOTATION AND TRANSFORMATION FOR ELASTIC COEFFICIENTS

The generalized Hooke's law (Cauchy equations) for a general

anisotropic material in terms of rectangular coordinates x,y,z are as

follows:

/ \a

XX

ayy

azz

°y*

axz

a1, xyj

» =

" Si

C0121

C21

C41

C51

C.,61

'12 "13

"22 "23

"32 "33

"42 "43

'52 "53

'63

'14

'24

'34

"44

'54

'64

'15

'25

'35

"45

'55

'65

C16

C26

C36

C46

C56

c"66

<

f -\eXX

eyy

Gzz

ey2exz

exyv J J

(A-l)

where 0. . and e.. are stress and strain components, and C . are the1 J 1 J Kit

Cauchy stiffness coefficients for a three-dimensional body. It can

be shown that the matrix of Cauchy coefficients is symmetric, provided

that the material is conservative (elastic) , so that

(A'2)

Usually a single layer of fiber-reinforced composite material has

the fibers oriented more or less parallel to the top and bottom surfaces

44

of the layer, i.e. material-symmetry plane XY coincides with surface

plane xy. Thus, it is orthotropic in the yz and xz planes, and the

shear-normal or cross-elasticity coefficients with subscripts i4 and

i5 (i=l,2,3,6) vanish:

/ \a

XX

°yy

azz

ayz

Oxz

o

=

12

12

22

13

23

33

44

45

45

55

16 26 36

—C16

C26

c36

Q

0

C66_

/ \exx

eyy

ezz

eyz

exz

,exy

The only exception to the above, i.e. the only case when the general

form (A-l), rather than (A-3), must be used is the case of a shingle-

laminated composite, as shown in figure A-l (reference 47).

If, in addition to being parallel to the top and bottom faces of

the layer, the fibers are also oriented in a direction parallel to one

of the coordinate directions in the plane of the layer, the material-

symmetry plates XY,YZ,ZX all coincide with the coordinate planes xy,

yz,zx and the material is said to be completely orthotropic. In this

the Cauchy relations are:

» . . . % . f N

r°xx1

°YY

>,

* -

* * *r r rCll C12 C13** * *

C12 °22 C23

* * *C13 C23 C33_

'

X^ '

6 XX

6YY

^ ;<1[ezzj

°YZ

\i

°XYV. y

Y =

*C44 £YZ*

C55 eXZ

*CM «XYDo XY^ s

(A-4)

45

where the asterisks denote the orthotropic case.

In the case of a thin layer of fiber-reinforced composite

material in which the thickness-normal stress (o77)can be neglectedLtC*

(see Hypothesis H3, Section 2.1), the third equation in set (A-4) can

be solved for e77 i-n terms of evv and e...,. Then equations (A-4) can be<£^ XX II

simplified as follows:

°xxj

1 =°YY

V ..'

r * * -\Qll Ql2

* **12 ^22

f e x x '

1*

eYYJ

' ;<

r %

°YZ

^CZ

SCY^ •/

> =<

f * 1Q44 6YZ*

Q55 exzQ66 eXY

^ ^/

(A-5)

where the reduced orthotropic stiffness coefficients are related

to the Cauchy three-dimensional orthotropic stiffness coefficients

(C. f) as follows:

* 2 *(C13> /C33

* * * *C ' (C C / C )

12

22

13 2 3 3 3

(ij = 44,55,66)

(A-6)

Equation (A-5) can be written in the form of a single matrix

equation as follows:

where

(A-7)

46

= <

( °xx 1

°YY

°YZ

°XZ

CXY ;

fcxx

6YY

5eYZ

^exz

5eXY

(A-8)

*

*'12

0

0

0

*

*Q22

0

0

0

0

0

2<4

0

0

0 0 0

(A-9)

where the presence of the factor 1/2 in the e matrix is used to makeLtj

it a second-rank tensor and this necessitates the presence of the factor

2 appearing in equation.(A-9).

In structural-panel applications of composite materials, usually there

are design requirements for multiple orientations of fiber-reinforced com-

posite-material layers. Therefore, it is essential that a set of trans-

formation relations be used to calculi .= the stiffness coefficients for

any desired orientation from that associated with the major material-

symmetry direction (fiber direction) as shown in figure A-2. Such

relations are developed in the ensuing paragraphs.

47

Arbitrary orthogonal axes in the plane of the laminate and making

an angle 9 with the material-symmetry axes (X,Y) are designated as

the x,y axes. Then the components of stress and strain can be trans-

formed from the x,y axes to the X,Y axes as follows:

[VJ (A-10)

(A-ll)

where joTTf and jeTTf are as defined in equations (A-8) ; 1 0. .f and

1e..r are similar except that the subscripts X,Y,Z are replaced by

the subscripts x,y,z; and [T 1 is the transformation, defined as

follows:

J =

2m

2n

0

0

mn

2n

2m

0

0

-mn

0

0

m

n

0

0

0

-n

m

0

-2mn

2mn

0

0

2 2m -n

(A-12)

where

m - cos 9 , n =- sin 9. (A-13)

For the case when 9 ^0, we have

In view of equations (A-7,A-10,A-11,A-14),

(A-14)

48

By substituting equations (A-9) and (A-12) and then performing

the matrix operations indicated in equation (A-15) the elements of

k»3 matrix are related to those of the [Qk»the [Q»3 matrix are related to those of the [Q»] matrix as follows

* 4 * * 2 2 * 4Qn = Qnm + 2 (Q12 + 2Q66) m n' + Q^n

* 4 * * *22 * 4Q12 = Q12m + (Qu + Q22 - 4Q66)m n + Q^n

* 4

* 4 * * * * 2 2 * 4Q66m + (^11 + Q22 - 2^12 ' 2(*t>6>m n + Q66n

n - <2(

= Q44m* 2 * 2

Q45 = Q55mn - Q44mn

Q55 - Q55ra* 2 * 2

49

APPENDIX B

MODELS AND MEASURES OF MATERIAL DAMPING

Bl. Mathematical Models for Material Damping

Internal friction or damping in materials can be caused by a variety

of combinations of fundamental physical mechanisms, depending upon the

specific material. For metals, these mechanisms include thermoelasticity

on both the micro and macro scales, grain boundary viscosity, point-

defect relaxations, eddy-current effects, stress-induced ordering, inter-

stitial inpurities, and electronic effects (reference 48) . According to

Lazan (ref.48), little is known about the physical micromechanisms

operative in most nonmetallic materials. However, for one important class

of these, namely polymers and elastomers, considerable phenomenological

data have been obtained. Due to the long-range molecular order associated

with their giant molecules, polymers exhibit rheological behavior inter-

mediate between that of a crystalline solid and a simple liquid. Of

particular importance is the marked dependence of both stiffness and damp-

ing on frequency and temperature.

The purpose of developing a mathematical model for the rheological

behavior of a solid is to permit realistic results to be obtained from

mathematical analyses of complicated structures under various conditions,

such as sinusoidal, random, and transient loading. According to reference

48, as early as 1784 Coulomb recognized that the mechanisms of damping

50

operative at low stresses may be different than those at high stresses.

Even today, after more than 2500 publications on damping have appeared,

major emphasis is placed on linear models of damping for several reasons:

they have sufficient accuracy for the low-stress regime and linear analyses

are computationally more economical than nonlinear ones.

The simplest mathematical models of rheological systems are single-

parameter models: (1) an idealized spring, which exhibits a restoring

force linearly proportional to displacement and thus displays no damp-

ing whatsoever, and (2) an idealized dashpot, which produces a force

linearly proportional to velocity. Obviously, neither of these models

are very appropriate to represent the behavior of most real materials.

The next most complicated models of rheological systems are the

two-parameter models: (1) the Maxwell model, which consists of a spring

and dashpot in mechanical series, as shown schematically in figure B-l(a);

and (2) the Kelvin-Voigt model, which is comprised of a spring in

parallel with a dashpot, as shown in figure B-l(b) . The Maxwell model

is a fair approximation to the behavior of a viscoelastic liquid. How-

ever, as a model for a viscoelastic solid, it has several very serious

drawbacks (reference 48); there are no means to provide for internal

stress and for afterworking. The Kelvin-Voigt model overcomes these

deficiencies and is a first approximation to the behavior of a viscoelastic

solid. However, it has the following disadvantages (reference 48): there

is no elastic response during application or release of loading, the

creep rate approaches zero for long durations of loading, and there is

no permanent set irrespective of the loading history.

51

It should be mentioned that the Kelvin-Voigt model is the simplest

one which permits representation as a complex quantity when subjected to

sinusoidal motion. To show this, one can write the following differential

equation governing the motion of a single-degree-of-freedom system con-

sisting of a sinusoidally excited mass attached to a Kelvin-Voigt element:

mu + cu + k u = F eiUJt (B-l)

where m = mass, c & viscous damping coefficient, k = spring rate, F s

exciting force amplitude, UJ H circular frequency of exciting force,

u s displacement, i = V-l , t & time, and a dot denotes a derivative

with respect to time. Assuming that sufficient time has passed for the

*transients to die out, we can write the steady state solution of equation

(B-l) as follows:

~ i(uut-cp) ~ r/1 2.^ . -,-1 i&t ,_ 0,u = u e = F [(k-muu )+ iuucj e (B-2)

where cp = phase angle between the response (u) and the exciting force,

and u s displacement amplitude.

It is noted that the terms containing Kelvin-Voigt coefficients k and

iac can be grouped into a single Kelvin-Voigt complex stiffness (k) as

follows :

*It can be shown that they do die out for a mechanical system, for which

c, m, and k are all positive quantities.

52

k = k + i'juc (B-3)

Alternatively, the Kelvin-Voigt element coefficient could have

been grouped into a single complex damping coefficient (c) as follows:

c = c - (i k/!i,) (B-4)

The force (Fd) in a dashpot is given by

F = c ii = i o i c u e " (B-5)d

The energy dissipated per cycle (U.) is a dashpot undergoing

sinusoidal motion can be calculated as follows:

P -2rr/ju ~U = A F.du =1 F u dt = nc.i-.7i (B-6)

o

In 1927, Kimball and Lovell (reference 49) observed that many

engineering materials exhibited energy losses which were contradictory

to equation(B-6). Specifically, they found that U, was proportional

~2to u but independent of ou, i.e.

(B-7)

~Later work by Wegel and Walther (reference 50)also showed that U , oC u

but C1 was a weak function of ju. Still later, for stresses below thed

2fatigue limit of the mater ial , Lazan (references 48,51) showed that U.oCu

and C was pract ical ly independent of x.d

53

Equating the energy dissipated per cycle in the Kimball-Lovell

material, equation (B-7), to that in the dashpot, equation (B-6), one obtains

C' = TTCUJ (B-8)

To utilize the Kimball-Lovell observation in practical structural

dynamic analyses, it was desirable to have an expression for the as-

sociated damping force, i.e. an equation analogous to equation (B-5), which

governs a dashpot. According to Bishop (reference 52) this was first done

by Collar. Combining equations (B-5 , B-8), one obtains the following

"frequency-dependent damping" relation:

Fd = (b/'ju) u (B-9)

where b is a constant given by

b = C'/TT (B-10)d

The kind of damping represented by equation(B-9)has been called fre-

quency-dependent damping, since the usual dashpot coefficient c is now

replaced by the quantity b/uj.

For the damper represented by Eq.(B-9),it is convenient to replace

k in the undamped system by the following Kimball-Lovell complex stiffness

(reference 53):

k1 = k + ib (B-ll)

where it is now noted that both k and b are assumed to be independent of

frequency. This representation has been used extensively in aircraft

54

structural dynamic and flutter analyses (references 54,55).

An alternative to equation (B-ll), is to use the concept of a complex

damping coefficient, originated by Myklestad (reference 56), in which the

spring constant is replaced by

k" = C eim (B-12)

where C.. and m are constants.

Although Kimball and Lovell's original work was based on data

obtained during steady-state sinusoidal motion, the models represented

by equations (B-9, B-ll, B-12) have been applied to free vibrations as

well (refs. 52,53,57). To alleviate the difficulty of the interpreting of

a; in equation(B-9)for the case of free vibration or for multiple-fre-

quency forced vibration, Reid (reference 58) suggested the following form:

Fd = b | u/u | u (B-13)

where the bars denote that the absolute value of the quantity between

them is to be used.

In summary, four different versions of material damping have been

discussed. In terms of the differential equation for free vibration,

they may be written as follows:

mu' + (b/.j,) u + ku = 0 (B- 14a)

mu + (k + ib) u = 0 (B-14b)

mu + Cl eim u = 0 (B-14c)

mu + bju/u | u + ku = 0 (B-14d)

55

The models represented by equations (B-14) have been criticized

by many investigators for various reasons:

1. In equation (B-14a), the interpretation of a. is dubious (refer-

ences 58,60). Milne (reference 59) suggested that it is associated with the

imaginary part of the pair of complex roots, but went on to state that

there is no clear justification for this interpretation.

2. Equations (B-14b) and (B-14c) are equations with complex coef-

ficients and the meaning of this is not clear (references 57,59) . Further-

more, although they have complex exponential solutions, neither the real

nor imaginary parts alone are solutions (references 59,60).

3. Equation (B-14d) is a nonlinear differential equation, due to

the behavior of |u/uj (reference 59).

4. None of the models represented by equations (B-14) can be sim-

ulated, even on a conceptual basis, on an analog computer (references

58, 60).

5. The model represented by equation (B-14a) does not meet the

Wiener-Paley condition (references 61,62) of causality for physically

realizable systems, as was shown in references 60, 63-65..

6. Equation (B-14b) fails to give the proper relations of a

damping force that is proportional to displacement and in phase with

velocity. This can be alleviated by use of a more unwieldy expression

proposed in references 66,67.

Incidentally reference 68 claimed that none of the equation

(B-14) models result in energy dissipation that is independent of

di (the reason for abandoning the Kelvin-Voigt model). However, an error

in this reasoning, which makes it invalid, was pointed out in reference

69.

56

It can be shown that the sinusoidally forced vibration version of

free vibration equations (B-14«,b,c) are exactly equivalent. Probably

the most popular form for writing this is as follows:

mu' + (k + ib)u=F elajt (B-15)

The major criticism of the use of equation (B-15) is that it results

in a conventionally defined magnification factor (see Section B2) , correspond

ing to zero frequency, which is not equal to unity for g / 0 (reference 52) .

This difficulty can be eliminated by redefining the magnification factor as

follows:

MF' = u/u' (B-16)S w

where

and k1 is the stiffness coefficient associated with the total in-plane force

amplitude, i.e.

k'5(k2+b2)*

Thus,

MF' = (k2+b2) /[(k-muJ2)2+ b2]* = (1 + g2)*/[(l-uu2/uu2)2+g2^n

The major advantages of using the equation (B-15) model for steady-

state vibrational and flutter analyses are as follows:

1. The analysis is considerably simplified in comparison with that

for viscous damping, as pointed out in reference 70.

2. The analysis is linear.

3. The complex -modulus concept has long been in common use, especially

57

in connection with measurement of the damping properties of elastomers,

polymers, etc. (reference 69).

4. The complex-stiffness approach has been used very successfully

in flutter analysis for approximately three decades refs. 54, 55, 69, 71).

In view of these considerations, the complex-stiffness approach is

used in the main portion of the present report. However, for completeness

and comparison, a number of other more complicated approaches are also dis-

cussed in this section.

To overcome some of the deficiencies of the Kelvin-Voigt and Max-

well models, they were combined in various ways to obtain the three-para-

meter models shown in figure B-l(c) and (d). It can be shown (reference

72) that by properly selecting the values of the coefficients, the two

models can be used interchangably. In other words, the model repre-

sentation is not unique. In fact, both representations have been called

the "standard linear solid", "standard linear material," "simple an-

elastic model", or "standard model of a viscoelastic body" (references

73-76). Unfortunately, few materials have been characterized by the use

of the standard linear solid. Perhaps the most extensive characterization

has been carried out for flexural vibration of 2024-T4 aluminum alloy:

by Granick and Stern (reference 77,78 ) in air and by Gustafson et al

(reference 79) in vacuo.

Obviously one can go on from a three-parameter model to a four-

parameter one, etc. Continuing this process, one obtains two well-

known models (reference 74): the Kelvin chain, shown in figure B-2(a),

and the generalized Maxwell model, shown in figure B-2(b). The be-

havior of such systems can be written in either differential or integral

form, as discussed in detail in reference 74. However, the complexity of

58

such a model has limited its use both experimentally (in characterizing

engineering materials) and analytically (in performing dynamic analyses).

Thus, for engineering applications, there is a continuing search for

models which are simple, yet represent the behavior of real materials

with sufficient accuracy.

A^relatively simple model, which is somewhat similar to the generalized

Maxwell one, is due to Biot (reference 80 ); see figure B-2(c) . The number of

simple Voigt elements in this model is allowed to increase without bound,

so that the damping force is represented by the following expression:

rtFd = 8lJ Ei [-e(t-T)](du/dT) dt (B-

*1where T is a dummy variable; e,g-i = parameters, end Ei(u) is the exponential

integral

r~u -£Ei (u) =1 (e /?)d? (B-18)

00

Caughey (ref. 60) made a detailed study of Biot's model for both

free and forced vibration. He showed that for a/e > 10, the energy dis-

sipated in Biot's model is within 4% of being independent of frequency

and thus essentially depends only upon the square of the displacement

amplitude. Milne (ref. 59) studied the Biot model by means of the con-

volution integral.

Neubert (reference 81) introduced a variant of the Biot model, in

which a different distribution function for the local stiffness-damping

ratio is used. Milne (ref. 59) also studied this model via the convolution

integral. Milne introduced a new synthesized model of his own. However,

59

the main conclusion of his investigation was that, for practical engineer-

ing purposes, the choice of a rheological model is not critical, provided

that the range of constant damping is kept the same and the damping is

sma 11.

The linear hereditary theory of material damping was originated in

1876 by Boltzmann (reference 82). In this theory, the energy loss is

attributed to the elastic delay by which the deformation lags behind

the applied force. It is called a hereditary theory because the in-

stantaneous deformation depends upon all of the stresses applied to the

body previously as well as upon the stress at that instant. The damping

force is given by

Fd = J *(t'T) u(T) dT

where t == actual time, T = an instant of time (dummy variable), u =

displacement, and § =• hereditary kernel or memory function. Often the

hereditary kernel depends upon the difference (t-T) only; then equation

B-19) becomes:

F, = *(t - T) u (T) dT (B-20)d v

It is most advantageous to determine the hereditary kernel from

experimental data. It has been found to be a monotonically decreasing

function which can be represented mathematically as follows:

n

$ (t) =yA..e"ait (B-21)

Such a system is said to have a heredity of degree n and A. and Q.

60

are called heredity constants. Hobbs (ref. 75) has shown that a first-

degree hereditary model is equivalent to a simple anelastic model

(standard linear solid).

Volterra (reference 83) has presented a method of determining the

hereditary kernel from material response to either suddenly applied

loading or to sinusoidal excitation. He also presented plots of mag-

nification factor and phase shift verus frequency for a wide range of

parameters of a single-degree-of-treedom system with first-degree

hereditary damping. For certain combinations of the parameters, the

magnification and phase characteristics are quite different from that

of a viscously damped system; yet for certain other combinations, the

characteristics are quite similar.

Numerous nonlinear mathematical models have been proposed to per-

mit better correspondence between theory and experiment. However, all

of them, by their very nonlinear nature, are more complicated to apply

in structural dynamic analyses of practical engineering systems. Perhaps

th« simplest one is damping energy per unit volume and per cycle pro-

portional to stress to a power (ref. 48):

Udv= Cdom (B-22)

where C. and m are material constants and <r is the cyclic stress

amplitude. It is noted that m=2 corresponds to the Kimball-Lovell re-

lation (linear theory) discussed previously. It has been found that m

varies from 1.8 to 6.0, generally being near 2.0 at low stress amplitudes,

The hysteresis loop associated with the complex-modulus model,

equation (B-ll), is elliptic in shape; see figure B-3(a). However,

61

the hysteresis loops determined experimentally have sharp corners at both

ends and are nearly linear in the low-stress, low-strain region, as shown

in figure B-3(b). According to ref. 48 (page 97), in 1938 Davidenkov

proposed a nonlinear mathematical model which results in a similar shape

of hysteresis loop. Further work on this class of model has been carried

out by Pisarenko (reference 84).

Rosenblueth and Herrera (reference 35) proposed a nonlinear model

which eliminates the causality difficulties of the complex-modulus model.

Chang and Bieber (reference 86) introduced a nonlinear hysteresis model '

in which there is no hysteresis damping unless the displacement amplitude

exceeds a certain threshold value.

B2. Measures of Material Damping

In this section, various definitions of damping are discussed in

the context of a complex-modulus material.

Energy Dissipation Under Steady-State Sinusoidal Vibration. - Energy

dissipated per cycle (U,) in the form of internal frictional heating is

one measure of damping. However, this quantity depends upon the size, shape,

and dynamic stress distribution (which in turn, depends upon the particular

mode of vibration). In view of the above difficulties, the specific damping

energy (U, ) is usually considered to be a more basic property of the

material. rather than the structure. The U, is defined as the damping energy

per cycle and per unit volume, assuming a uniform dynamic stress distribution

throughout the volume considered. Thus, the total damping energy is

U. = <p IT dV (B-23)d J dv

62

where V -.- volume. The usual units of U, are in-lb/cycle and of U. ,d dv

in-lb/in -cycle.

Resonant Magnification Factor Under Steady-State Sinusoidal Ex-

citation. - The resonant magnification factor (RMF) is defined as the

dimensionless ratio of the response at resonance to the excitation,

where both the response and the excitation must be specified in the

same units (see figure B-4). These quantities may be in units of dis-

placement, velocity, acceleration, or strain. Unfortunately, the re-

sonant magnification factor is dependent upon the structural system con-

figuration as well as upon the damping property of the material, so that

it is considered to be a system characteristic, rather than a basic material

property.

Incidentally RMF is not applicable to nonlinear systems, since then

it depends upon the excitation level. (In a linear system, RMF is independ-

ent of the level of excitation.)

Bandwidth of Half-Power Points Under Steady-State Sinusoidal Excitation.

The separation (uu-iu..) between the frequencies associated with the half-

power points increases with an increase in damping (see figure B-5) and thus

can be used as a measure of damping. A more meaningful definition is to

normalize by the associated resonant frequency (uu ), i.e. use the dimension-

less bandwidth given by:

- a; )

This measure is the basis for determination of damping by the original

Kennedy-Pancu method (reference 87).

The quality factor Q is defined as the reciprocal of the dimensionless

63

bandwidth.

Derivative of Phase Angle with Respect to Frequency, at Resonance.

This measure is the basis for determination of damping by an improvement

(reference 88) of the Kennedy-Pancu method.

Loss Tangent Under Steady-State Sinusoidal Excitation. - Applying

the complex-stiffness (see Section Bl) to the material property represent-

ing stiffness, namely the Young's modulus (E), we obtain

E - ER(1 + ig) (B-24)

*Thus, the loss tangent is defined as follows:

g ? El/ER (B-25)

I ** R ***where E = loss modulus and E is called the storage modulus.

Referring to figure B-6, we obtain the following relation:

g = tan Y = ET/ER (B-26)

or

v = arctan EX/ER (B-27)

*Also known as the "loss coefficient", "loss factor", or "damping

factor".

**Also sometimes called the "dissipation modulus."

***Also sometimes called "elastic modulus" or "real modulus."

64

The quantity Y is called the loss angle and equation (B-26) explains

the origin of the term loss tangent for g.

Cyclic Decay of Free Vibrations. - In a linear system, free vibrations

decay exponentially (see figure B-7). The larger the damping, the faster

is the decay. Thus, the logarithmic decrement 6 is defined as follows:

6 = in (3,/a. J (B-28)

where Ln ^ natural logarithm.

For a power-law material, eq. (B-22), to have 6 independent of

amplitude, m must be 2 (see Section B3 for proof). When m=2, the follow-

ing means of calculating 6 is more practical, especially when damping

is small:

6 = (1/n) t.n (a./a ) (B-29)

where n is any arbitrary integer.

Temporal Decay of Free Vibrations. - Another measure associated with

the decay of free vibrations is the temporal decay constant v , defined as

follows (reference48, foldout opposite p. 35):

vt - (tj-tj)"1 >,n [u(t1)/u(t2)] (B-30)

where t, and t_ are two different values of time, arbitrary except that

t~ > t1 and (t~ - t ) must be an integer number of periods of damped

vibration. The quantities u(t.) and u(t2) are the respective displacements

at times t, and t2. It is seen that the usual units for v are sec

65

An alternate way of specifying the temporal decay is the decay

rate v , which has units of decibals per second (db/sec) and is defined

as follows:

or

t - 20 (t2-t1)"1 log [u(t1)/u(t2)] (B-31)

-1 Vt(t2"tl)Yt = 20(t2-t1) log e = (20 log e)vt ** 8.68 V(;

where log = logarithm to the base 10.

Spatial Attenuation of a Plane Wave in a Slender Bar. - If

one propagates a plane, harmonic wave in a slender bar made of a homo-

geneous, linear material, the wave exhibits exponential decay with axial

position (x), analogous to the temporal decay of free vibration (which

may be consiered as a standing wave). Analogous to the logarithmic de-

crement (see above), we have the logarithmic attenuation 6 , defined ass

follows in terms of amplitudes a(x..) and a(x~) at stations x.. and x?:

6S = [a(x1)/a(x2)] , (B-32)

Analogous to the temporal decay constant, we define the spatial

attenuation constant v as follows:. s

vs 5 <X2'X1)"1 '-n Ca(x1)/a(x2)] (B-33)

The unit of v is in" .s

Finally, analogous to the decay rate, we define the spatial

attenuation rate y as follows:~ S

66

Ys - 20(x2-x1)"1 log [a(x1)/a(x2)] ~ 8.68 v^ (B-34)

The unit of y *s db per unit length.8

It should be cautioned that the determination of damping by wave

attenuation requires that the cross section of the bar be compact (pre-

ferably round or square) and that the largest cross-sectional dimension

be very small compared to the wave length of the traveling wave. Further-

more, the two stations along the bar, at which the wave measurements are

made, must be: (1) sufficiently far from the point of impact that initial

transients have died out and (2) sufficiently far from each other so that

a measurable change in amplitude occurs. Kolsky discussed these points

in detail in reference 89 .

1

B3. Inter-Relationships Among Various Measures of Damping

for Homogeneous Materials

Here we consider a single degree-of-f reedom system consisting of a

mass supported on a mass less spring made of a homogeneous Kimball-Lovell

or complex-modulus material. Then the governing differential equation

for simple harmonic excitation is equation (B-15), which has the following

steady-state solution:

u = u e " (B-35)

where

u ? F [(k-mo2)2 +b2]'1/2 (B-36)

rp s arctan [b/(k-tmu2) ] (B-37)

The magnification factor (MF) is defined as fol lows:67

MF = u/u (B-38)8t

where u is the so-called static displacement, defined as follows:S L

u = F/k (B-39)S C

Combining equations (B-36, B-38, and B-39), one obtains the

following relation:

MF ={[1 - (uj/u, )2]2+ (b/muj2)2 }"1/2 (B-40)I n n J

where u; is the natural frequency (i.e. the resonant frequency of the

undamped system) , given by:

1 /2a, = (k/m) ' (B-41)n

The critical material damping coeff ic ient (b ) is the minimum value

of b for which the free vibratory motion is non-oscillatory. It

is obtained from the following relationship:

2 2(b /2mu.' ) = k/m = uue n n ,

or

b = 2mu. 2 (B-42)e n '

The damping ratio £ is defined as follows:

C - b/bc (B-43)

Combining equations (B-40, B-42, and B-43), one arrives at the

following general, dimensionless relationship: ,„

MF = {[l-(uu/U)n)2]2 + 4£2}~1/2 (B-44)

It is seen easily that MF is a function of only two parameters: the fre-

quency ratio (ii)/uu ) and the damping ratio (Q . It should be mentioned

that equation (B-44) is somewhat different than the known relationship

for a single-degree-of-freedom Kelvin-Voigt viscously damped system,

even though the damping ratio £ is defined analogously ( = c/c ,

where c = 2moj ) .c n

The resonant magnification factor (RMF) is defined as the value

of MF at resonance, which is taken here to occur when cp = 90 . In view

of equation (B-37) , this implies that the resonant frequency is ou .

Thus, at resonance, equation (B-44) reduces to the following simple

expression:

RMF = (2£)-1

(B-45)

Thus, it is seen that the same simple relationship between the damping

ratio and the resonant magnification factor holds as does for a Kelvin-

Voigt system. Although the resonant amplitude can be measured accurately,

there are problems in measuring the static deflection in complicated

structures (due to signal-to-noise ratio limitations of instrumentation).

For this reason, in structural dynamics, RMF is seldom used as a measure

of damping.

The damping energy, i.e. the energy dissipated per cycle, can be

computed as follows:

U, = J> FJ du = j F,u dt (B-46)d J d J do

where F. is the damping force, given by

69

(B-47)

Substituting equations (B-35) and (B-47) into equation (B-46) and

integrating, we obtain the following result:

U. = rrb 1? (B-48)d

To convert equation (B-48) to the form of equation (B-22) , with

m=2 , it is necessary to divide by the volume and to relate 11 to Cf.

Now the force amplitude is

? = Aa = kii (B-49)

where A - cross-sectional area.

Assuming the spring is a mass less and uniform bar, we have

k = AE/L (B-50)

where L z effective length of spring and E •-= Young's modulus of the bar.

Combining equations (B-48, B-49, B-50), one obtains the following result;

j " UJ/V • (nbL/A) (o/E) 2ds d

Comparing the form of equations (B-22) and (B-51) , we see that

for a Kimball-Lovell mater ia l , m = 2 and

C. = TtbL/AE2 (B-52)d

It should be noted that Lazan (reference 48 , chap. II) has shown

that these results are independent of the stress distribution and the

specimen geometry, provided that ra = 2.

70

In view of equations (B-42, B-43, and B-44), equation (B-52) can

be expressed in the following more useful form:

C = 2ir (B-53)

According to equation (B-48) , the damping energy (and thus,

excitation power) is proportional to the square of the displacement

amplitude u (and thus, the MF). Then the power is one half of what it

is at resonance when MF = RMF//2. In view of equation (B-45), the half-

power magnification factor (HPMF) is related to the damping ratio as

follows:

HPMF = RMF//2 = (2/2 Q~l (B-54)

To determine the two sideband frequencies (j; = uu. and sO cor-

responding to half power, we combine equations (B-44) and (B-54) to

2obtain the following quadratic expression in n; :

(2/2

which has the following positive roots:

a;. , = a; (1±2 f)* (B-55)1 ti n

It is interesting to note that equation (B-55) is identical to the analogous

2expression for the lightly damped Kelvin-Voigt system, i.e. (c/c ) « 1.

For small damping (C « ^),

*1>2 * (i ± 0 %71

Thus, we get the following relation between the dimensionless bandwidth

and the damping ratio Q:

2£ (B-56)

In the original Kennedy-Pancu method (reference 87), this relationship is

used to determine the damping ratio from the geometry of an experimentally

determined Argand plot (a polar-coordinate plot of response amplitude

versus phase angle).

In terms of the quality factor Q, equation (B-56) may be rewritten

as follows:

Q ~ (2C)"1 (B-57)

It is interesting to note that in order for the half-power frequencies

to be real, the damping ratio £ must be no greater than /2/2 <** 0.707. How-

ever, this is not a severe limitation for actual structural materials.

The potential energy (strain energy) stored in our single-degree-of-

freedom mathematical model is given by:

(B-58)U = 4> F dus

where F is the spring force, given byS

F = kus (B-59)

Thus,

U = k J u du = ku2/2

Combining equations (B-48) and (B-60) , we obtain

U /U = 2rrb/kd

(B-60)

(B-61)

72

Using equations (B-41, B-42, B-43), we can rewrite equation (B-61)

in the following more useful form:

U,/U =d

or

C = (1/4TT)(U./U)d

(B-62)

(B-63)

The loss tangent is defined as follows for the system considered

here:

g = b/k (B-64)

Inserting equations (B-41, B-42, B-43) into equation (B-64) we

obtain the following useful relationship:

(B-65)

The following useful relationship, which is sometimes taken as a

fundamental definition of damping (reference 66), is obtained here by

combining equations (B-63) and (B-65):

g = 2C

g = (1/2TT)(0./U)d (B-66)

Taking the derivative of phase angle rp with respect to frequency

one obtains the following result from equation (B-37) :

dcp/du, = 2biW[(k-mu;2)2+b2] (B-67)

At resonance (subscript R) , defined by UF=UU = /k/m, equation (B-67)

becomes:

(dcp/do;)_ = 2mu. /bR n (B-68)

Combining equations (B-42, B-43, and B-68), we obtain the following

73

very useful result:

[uu (dqp/duj) ]n K-1

(B-69)

It is interesting to note that although the MF vs. ui relation,

equation (B-44), is different than the corresponding relation for a Kelvin-

Voigt viscously damped system, equation (B-69) is identical to its cor-

responding relationship for a Kelvin-Voigt system. Equation (B-69) is used

to determine the damping ratio from an experimentally determined Argand

diagram in the improved Kennedy-Pancu method (reference 88).

The transient solution of the system represented by equation (B-14a)

can be written as follows:

u' = 1J'e ' n sin (/l-£2 0) t - <p) (B-70)

From its definition in equation (B-28), the logarithmic decrement 6

can be determined as follows:

6 = In

where T is the period of damped oscillation, given by

T - (2TT/-JJn)d-C? -1/2

Thus, we now have

(1-C )2,-1/2

(B-72)

(B-73)

For small damping (£ «1) , equation (B-73) can be replaced by the

following approximate expression:

(B-74)

74

6 = TTg

Combining equations (B-65) and (B-74), one obtains the following:

(B-75)

In view of equation (B-63) and since the specific energies are

given by:

(B-76)

we have

, /4nUds s (B-77)

However, the specific strain energy is

U = o /2Es

(B-78)

A power-law-damping material is defined by equation (B-22).

Combining this relation with equation (B-78), one obtains:

(E C/8TT)om"2 (B-79)

Thus, it is clear that £ is independent of stress amplitude only for a

KL (Kimball-Lovell) material (m=2). Then

(B-80)

or, in view of equation (B-65),

g = E Cd/4rr (B-81)

Furthermore, since the logarithmic decrement of a KL material with

small damping is approximately proportional to the damping ratio as shown

by equation (B-74), the following approximate relation holds:

6 » E C./4d (B-82)

75

APPENDIX C

DERIVATION OF ENERGY DIFFERENCE

It is assumed that the generalized coordinate | and generalized

force f have the following forms:

(C-l)~ iuut

f = q e

where 5 is a complex form representing %» 0' 0» x and 1 •

The strain energy can be expressed as

n. t»U =

where Q.. are stiffness coefficients and U is the amplitude of the strain

energy given by:

n nU =(1/2) Y Y Q ? r (C-3)

i-> i-> ij i J

For the damping energy, a dissipation function suitable for material

damping (reference 90) is developed. Hence, we introduce a dissipation

energy function for material damping as follows:

n n n n(bij /UJ> Si 'Sj "< l u > / 2>I lQlj?Jje

2lUit"(i«)5e2la*.i-1 j-1

(C-4)

76

where b.. are structural damping coefficients, Q = ib.. and D is the

amplitude of dissipation energy given by:

n nA. ~,

The kinetic energy of the system is

(C-6)

where m . are inertia coefficients and T is the amplitude of kinetic

energy given by

n n

T = (a2/2) V Yn,^ |. (c-7)

The work done by the uniformly distributed normal force is

n

W = f Z ?i= B -21" <c-8)

where q is the amplitude of the normal pressure and W is the amplitude of

the work done

W = q ?. (C-9)

The Lagrangian equation takes the following form (reference 91)

77

Each term of equation (C-10) can be expressed in terms of its

amplitude as follows:

d ,0TX oT icut oD SD iuut=-~ e ' = ~ e

(C-ll)

dU at! iuut , W aw iuuti S -^— p f = — — = ^-» (3

a? ' a? ai

With equations (C-ll) introduced, one can rewrite equation

(C-10) as follows:

flllf"

(T + W - if - D) e E = 0 (C-12)

or

|~ ( T + W - U - D ) = 0 (C-13)o^

Equation (C-13) is analogous to one presented by Volterra (reference 83 ).

Thus, the amplitude of the Lagrangian energy difference can be

expressed as follows

L = (T + W) - (U + D) (C-14)

when used in conjunction with Hamilton's principle, expressed in equation

(36).

78

APPENDIX D

COMPLETE ENERGY EXPRESSIONS

Dl. The Energy Difference

M N 1 1

^T 7 f f {(A11/a2)(U 4' 4 )2+(2A10/ab)(U 4' f ) (V $ 4' )L L J J I 11 mn um un v 12 mn um un ran vm vn

m=l n=l 0 0

+2A.,(a"1U 4' $ Xa-1V 4' $ +b~1U $ 4' )16 mn urn un mn vm vn mn um un

+2A,,(b~1V I 41 Xa-1V 41' 4 +b~1U f 41 )+A,,(a"1V 41 $ +b~lumn$,,m

$1',n)

26 mn vm vn mn vm vn mn um un 66 mn vm vn mn um un

+2B 1 1(a~ 1U $' $ ) (a~\ 4' * )+2K.J(a~ lV 9' 9 Xb~*Y 4 41

11 mn um un xmn tyxm tyxn 12 mn um un ymn ^ym fyyn

+bV $ $' X a " ^ *', *. ) ] + 2 B . _ ( b " V $ «' X b " ^ 4 $' )mn vm vn xmn \|ixm \lixn 22 mn vm vn ymn fyym 4'yn

+2B1 ,L(a"1U $' $ Xa"1^ $' $. 4-b"^ *, *,' )+a"1V *• $16 mn um un ymn y ym ipyn xmn \)fxm fxn mn vm vn

+b"1U $ 4' Xa-1Y $,' *. )]+2B0,[b"1V $ $' )(a" l vC •*,' $.mn um un xmn \ j ixm 'Jlxn 26 mn vm vn ymn \j; ym ty yn

+b"1'if f, $! )+(a"1V $' $ +b~1U $ *' Xb'S $, $.' )]xmn \J|xm \jixn mn vm vn mn um un ymn ty ym jjiyn

+2B,,(a"1V *' * +b -1U $ $' ) (a" 1 Y 4 ft -t-b"1^ $ 4' )66 mn vm vn mn um un ymn di ym \|f yn xmn \jixm \ J jxn

+ (D 1 1 / a 2 ) ( > f »' 4 ) 2+(2D 1 0 /ab) (^ 4,' $ , ) (Y * 9' )11 xmn i|;xm ij;xn 12 xmn 'ty xm i|/ xn ymn ^ ym ty yn

+(D 0 0 /b 2)(Y * 4' )2+251,(a"1Y *' f Xa"1^ *' $22 ymn \|i ym \(| yn 16 xmn ty xm ^ xn ymn ^ ym ^ yn

+b"1Y 4 *.' )+2D.,(b"1Y 4 4' Xa"1* f 4 +b"1V $ 4' )xmn \|l xm i|( xn 26 ymn 'Ji ym ijjyn ymn (jiym \(i yn xmn ^ xm ^ xn

+D,,(a~ lv 4' 4 +b"LY *. 4' )2+K A (a"1W $' $ +V $ f )66 ymn \|fym \|) yn xmn >Ji xm \j/xn 55 55 mn wm wn xmn ^ xm ^ xn

+2K. /-A / . (a"1W $' 4 +v * * ) (b"^ * 4' +w 4 $ )45 45 mn wm wn xmn \jixm ij( xn mn wm wn ymn ijiym ^ yn

ab do-+ K / / A / / ( b ~ 1 W $ 4' +Y 4 4 )Z\44 44 mn wn wn ymn tyym tyyn •»

M N ! i

-(iii2/2) T Y f [ fm [(U $ * )2+(V $ $ )2+(W $ $ )2]L Li 3 •) L o mn um un mn vm vn v mn wm wn J

m=l n=l 0 0

+2m,[(U * # )(Y 4 4 )+(v 4 * )(* 4 4 )]1 mn um un xmn ty xm i|J xn mn vm vn ymn ty ym ly yn

79

,[(Y '4. 4. )2-(-(Y ». *. )2]} ab do- dpI xmn \jixm \jixn ymn \liym i|iyn J p

M N 11

Z V f I - (D-l)) q W * 4 ab dor dpL> J J mn wm wn

where

D2. Equations for Minimizing the Energy Difference

N

If I 6' *' A~ I * T v

un u-f/1 1 ° Om=l n=l

M

M, N 1 19L/9U. = (b /a )A } T U f *' *' dor f

k-C 11 £_, L, mn .1 um uk Jm=l n=l ° °

• \ ^ r1 r1 ,L _ / / V $ $ . do< $ $ .dB12 L L> mn J vm uk J vn uf.

, , o om=l n=l

M NM IN 1 iv v r r

+(b /a )A, . ) ) V i $' $ ' , d f y $ $ .dp16 £j Zj mn J vm uk ' vn u-f. H

, , o om=l n=l

M NM IN i iv v f r

+A,, } ) U * *', do/ $' * .dp16 Lt I, mn I "um'uk J un ul

i O On=l

- v f r1 r1+An , / ) U 4' * .dor 4 4 ' . d p16 '— i_i mn J um uk J un u-t

m=l n=l o °

+(a/b)A9 , y TV f 4 $ .da f 4' 4' dp26 L- i-> mn J vm uk J vn u-f,

m=l n=l

M NT r v r , r *,+A,, ) /' V i $ $ . da' 1 $ $ .dp

60 Li i-j mn J vm uk J vn u-f.n=l

M N

+(a/b)A,, y y U I 4 * .do I" *' * ' .dp66 L^ ' L-i mn J um uk J un u£m_l i O Om=l n=l

M N l 1

11 7 7 f f $' $ ' d a f $. $ .dp11 L: L> xmn J toon uk J 'Jrxn u-o

1 1 ° °m=l n=l

80

M Nv v r r ,j y / Y 1 $ 9 d o / 1 $ $ d

12 L. £_. ymn J ijiym uk J ijiyn u{.m=l n=l

1+(b/a)B., } Y Y i $! ty'.da | $ $ ,dfi16 L*. L-. ymn j uiym uk J iliyn u-f-m = l . o o ™n=l

M Nv v r r+Bit / / Y $ $ , da $' * ,dBID Z_j i_i xmn J \(ixm uk J \(ixn u-C

m=l n=l ° °

M N i iT V f P+B / ) Y $' $ da $ f' d 6

16 LJ L. xmn J \l|xm uk J ibxn u-f.m=l n=l

M N 1

+(a/b)B9 , y y Y f $. f ,c2o i_t LJ ymn J ^iym uk

1 1 ° " °m=l n=l

M NV V P , i. P+B,, / ) Y $ * da i 9 * dp

66 ^ £j ymn J i|;ym uk J \j,-yn u-t-m=l n=l

M N , ,v v r r1

+(a/b)B,, ) } Y $, * ,da » '• * ' d p66 /_, /..- xmn J ijixm uk J \)jxn u-f,

m=l n=l

M N2 r- r-. p1 p1

-ab u, ) ) m U # * . da * * .dpLl, o mn J urn uk J un -uf

m=l n=l

2 M * rl ri-ab u/ / i m v . $ $ da i 9 9 d8 = 0 (D-2)

L, L> 1 xmn . "'J«m uk J itocn u/.. . o f o Y

m=l n=l

There is another equation, for 5L/5V .=0, which is analogous to eq. (D-2)

with the following substitutions:

u**v , U4-»V, x-»y, 1«*2, $*-*•*', a4* b. (D-3)

81

Nv(b / a )K A Y Yw f $' $ ' d o < f $ $, dB

5-> JJ *-• <L mn J wm wk J wn w-f- H

m=l n=l ° °

M~~ ^ r1 r1

' 4. 4'. da 4. 4 $ .dpxmn J wxtn wk J then wxn w-f,m=l n=l ° °

ft A .1 -I) ) ¥ 4 , 4 ' , da 4.L^ L* xmn J pctn wk J i|i=l n=l C

M N 1 i

+K A Y Yw f 4' 4 ,da f 4 S ' . d B45 {,*. L> L, mn J wm wk J wn wt-* i , o om=l n=l

M N 1 1+K,,A. Y Yw [4 4 ' , d a f 4' 4 ,d645 45 L L mn J wm wk J wn wt v

m=l n-l ° °

M N i i

) Y f ) 4. 4 .da f $. 4 ' . c/L £_ xmn J u[xm wk J wxn w-f,1 1 O O *m=l n=l

M N l 1

+b K,, .A, Y Yv [4. 4 ' . da f 443 45 L. L. ymn J tyym wk J J. ,ymn J \|iym wk J \[iynm=l n=l ° °

" " 1 1+ ( a / b ) K / / A / . } Yw f 4 4 ,d» | 41

44 44 L L mn J wm wk J v1 1 ° °m=l n=l

M N 1 1+aK, ,A , y Yf f 4. 4 ,da f f. «' dp

44 44 L, L ymn J \|iym wk j ipyn w-f,1 * O «n=l

M N i i

-ab a-2 Y Y m W f 4 4 .da f 4 4 .dBL. LJ o mn J _ wm wk J _ wn we

n=l

M Nr." . r1.

(D-4)

M N 1 1

I I J $wk

d" Jm=l n=l

M NP1 P1

,<*P

M N 1 1$,, Y Y U f 4' 4' da f <11 L> L, mn J um ibxk Jum \||xk J un

m=l n=l u °

82

& N

) VL V

+B, \ ^' -112 L ±:-!•-*»*>! *' *n=1 o vn

M

f f v r1

16 ^1 *- mn J *' »;ri

o j $ «m=i n=i o - T—V JQ vn

M N

*1 n=l

f fv T1^26 L> L\n J $

vm^xm=l n=1 o vm fx

M N+B > V f1 1

'-' ^ mn J vm^tej.dQ'= vm Xk

.1f

J

n=l

66 A ^,-".*-ltafc* ff..:,:

M ^fn Z >f r1^ -i

m=, _^ Xmn -„**»p

m=1 n Xm" -

"

M N+(b/a>6.6 7 Tt fV ,. „ r'

^ n. W" J

0*»^f|«* J

+6 T V\ f1 r

^ c, xmn J **xmWdor Im=l = o **m fxk J— ^ xmn .j temTfrxk^ *, *' dftm=l n=1 o ^m vxk J^ ifrxn ^ °

? #

^ «i=1 n=l o

83

M N 1 1+(a/b)D,, y y? f $, $, .da \ *'. *'. .dp

26 <L i-i ymn J tyym \jixk J tyyn tyx*.m=l n=l

M N ! L

+6AA Y 7 v f $1 *, ,d<* f *, $! ,dPoo Z_, /_, ymn J \|iym ijix-f. J \|iyn lyxtm=l n=l

M N i j

+(a/b)D,, V Vur f 4 f, d« f »! $' .dp66 L. L xmn J tarn \bck J ten \lix-t0 T Y 0 Y

m=l n=l

M N j !

c C A C c y Yw f $' $. ,da f | * .dp55 55 L /L mn J wm \|ixk J wn \(rxtm=l n=l ° °

PA ("•+ab K^Ar r ) ) Y *. *. ,da $, * .dp

55 55 ZL £j xmn J tyxm \Jixk J i|ixn \jpc-tm=l n=l

M. N 1 1+a K, CA. c Y / W I $ *, ,d<y | $' $, ,dB

45 45 ^ L mn J wm 'jixk J wn Ax-t H

1 1 ° °m=l n=l

^ A ,1 .1

+3b K45^5 m=l n=l

M N ! 1

-ab uo / ) m.U $ $. .do/ $ $, .dpZ^ Z-. 1 mn J urn wxk J un ta-t, p

, , o o Y

m=l n=lM N T !

. 2 m ^ $ , * , i d o ^ , * , , d p = 0 (D-5)-ab uu L L 2 xmn J \|ixm \jixk .1 i|ixn i^x', K

m= 1 n= 1

There is an analogous expression for SL/W k>=0. using the trans-

formations (D-3) , plus the following additional one:

45** 55 (D-6)

84

APPENDIX E

DERIVATION OF THICKNESS-SHEAR FACTOR FOR THE THREE-LAYER,

SYMMETRICALLY LAMINATED CASE USING THE DYNAMIC APPROACH

El. Dynamic Elasticity Analysis of an Individual Layer

Undergoing Pure Thickness-Shear Motion

For an individual layer undergoing pure thickness-shear motion

in the xz plane, the only non-zero strain component is e • Now itX Z

is assumed that the layer is orthotropic, so that the only non-zero

stress component is o , given by equation (49). Then the generalx z

stress equations of motion for three-dimensional, dynamic elastic

theory reduce to the following two equations:

o = pu. . ; o = pw,.. (E-l)xz,z K tt xz,x tt

The longitudinal thickness-shear strain can be calculated from

the displacements (u,w) in the x,z directions, respectively, as follows:

exz=U'z+W'x

The following displacement equations of motion are obtained by

substituting equations (49) and (B-2) into equations (E-l):

cs(u*zz + "•*«> = U'tt ; Cs(u'xz + w'xx) = w'tt (E'3)

85

where c Is the shear wave-propagation velocity defined by:s

=C55/p (E-4)

However, for pure longitudinal thickness-shear motion, the dis-

placements are independent of axial position x. Thus, all derivatives

of displacements with respect to x vanish and equations (E-3) reduce

to the following single expression:

cs u'zz = u>tt

Equation (E-5) is the familiar, one-dimensional wave equation,

which is solved easily by the separation-of-variables method, with the

following solution for simple harmonic motion:

u(z,t) = (A cos Q z+B sin 0 z)(C cos At + C« sin u>t) (E-6)S 8 L £

where Q s uu/c , A and B are constants depending upon the boundaryS S

conditions, and C. and C2 are constants which depend upon the initial

conditions.

E2. Dynamic Elasticity Analysis for Three-Layer,

Symmetrically Laminated Case

Here we consider the special case of a three-layer, symmetrically

laminated member, in which the two identical outer layers are designated

by superscript 1 and the middle layer is denoted by superscript 2, as

86

shown in figure E-l. The proper boundary conditions for the anti-

symmetric modes in pure thickness-shear motion are

(z2,t) = u(2) (z2,t) ; u. 0 ;

u,z(2)(z2,t) ; u

(2) (0,t) =0

(E-7)

where z1 and z_ are dimensions shown in figure E-l.

Substituting equation (E-6) into equations (E-7) yields the follow-

ing set of expressions:

cos + B sin cos

+ B0 sin fl z. ; - 0 A, sin 0 z_ 4- 0 B, cos2 s 2 s 1 s 2 s 1

V ' A «:-in (V~' •* 4- O v~' R ro«i O x ~ ' z • -O V * 'A < ? i n »-)x"' ?4 o ^ a l l l H Z~ * \ t O ^ C U o ^ i ^— > — \ l n o i n i cs 2 s 2 s 2 s 2 s 1 s 1

B. cos n z. = 0 ; A_ = 0S 1 S 1 i

(E-8)

or

cos s

sin

sin 0(1)z,S fc

.s i

8 lna< 2>, 2 -

)s(2)cos n^2 )z2

0 _

/ \Al• B l

J

» = 1

0

0

0V /

(E-9)

The homogeneous system of linear algebraic equations (E-9) has a

nontrivial solution if, and only if, the determinant of its coefficient

87

matrix is equal to zero. The resulting determinants1 equation has as

its solutions the roots of the following transcendental equation:

0(1) tan nf z, - - n<2> cot CO z, - n «.) (E-10)S S £ S S £ S L

(k) (k)From the definitions of Q and c , we have

S

where

P — P^ ' /P^ ' . P = rA ' /r,' ' ft} 1O\- ^55 '^55 > K P 'P V.i-l^;

Then equation (E-10) can be expressed as follows:

tan ( C n z O / R ) = cot

where

E3. Dynamic Analysis of a Symmetrically Laminated Timoshenko

Beam Undergoing Pure Thickness-Shear Motion

*Here we consider a symmetrically laminated Timoshenko beam . The

*A beam exhibiting both thickness-shear flexibility and rotatory

inertia is generally referred to as a Timoshenko beam (refs. 41,42).

88

axial and thickness (or depth) directions are designated as the x and z

axes, respectively. Such a beam could be analyzed as a special case of

the laminated plate theory presented in Section II by merely deleting

all derivatives with respect to y. However, the beam case is so much

simpler and pure thickness-shear motion is such a simple type of motion;

therefore, it was decided to make an exact analysis for the present case.

The following kinematic relations hold throughout the entire

thickness of the laminate:

K =ilf 5 e =w +\li (E-15)XX *X,X XZ 0,X *X

The following stress-strain relations are applicable to a typical

layer "k":

l H z ; a =xx 11 xx 11 xx xz 55 xz

The bending moment and shear force, expressed on the basis of a unit

width as in plate theory (Section 2.3) are:

n

oz dz ; QJ xx

n kM = o(k)z dz ; Q =Y | ok) dzL. Jxx

k=l Vl k=l Zk-l

Substituting equations (E-15) and (E-16) into equation (E-17) and

introducing the shear factor K,c as a correction factor to be determined

later, one obtains:

Mxx = Dll*x,x ;

39

where

zkk=i Vi

The equations of motion for a symmetrically laminated Timoshenko

beam are identical in form to those governing a homogeneous Timoshenko

beam (refs. 41,42), namely:

Q = m w ;M -Q= m.* (E-20)x,x o o,tt xx, x x 2Yx,tt

where m and ou are defined in equations (28) .

Inserting equations (E-18) into equation (E-20) , one obtains the

following set of two coupled equations of motion in terms of the generalized

displacements w and \li :

K55A55 (w0,xx+*x,x> =moW

0,tt

*x.tt

For pure thickness-shear motion, w and \|i are independent of axialo x

position x, so that equations (E-21) and (E-22) uncouple and become:

Wo,tt =°

m 2 * x , t t + K 5 5 A 5 5 * x

Since equation (E-23) does not contain K,.,. and since w is not

90

in equation (E-24), we have no further need for equation (E-23).

For steady-state harmonic motion, the solution of equation (E-24)

can be expressed as follows:

s1"* (E-25)

where ^is a constant.

Substituting equation (E-25) into equation (E-24), we are led to

the following relationship:

a.2 = K A/m (E-26)

This equation is applicable to any symmetrical laminate. For the special

case of a three-layer one, using the notation depicted in figure 10 and

the definitions of A,., and m- from equations (E-19) and (28), one obtains:

u>2 = 3K55 z~2 (C )/p(1))[(C2/P) + 1-C2]

(E-27)

' [(G2/R) + 1 - Cj I"1

where g,R, and £2 are as defined previously.

E4. Determinations of the Thickness-Shear Factor

The longitudinal thickness-shear factor, K , is determined implicitly

2by equating u/ associated with the lowest non-trivial solution of equation

(E-13) to that given by equation (E-27).

91

APPENDIX F

COMPLEX STIFFNESS COEFFICIENTS FOR A LAMINATE HAVING

ALTERNATING PLIES OF TWO DIFFERENT COMPOSITE MATERIALS*

Fl. Introduction

The theory presented in Section II can be used to calculate the

stiffness and damping coefficients for an arbitrary laminate, i.e. one

consisting of any number of plies of any thickness, material, and orienta-

tion. However, in many cases of practical importance, laminates are de-

signed to have many plies of two alternating materials. In such cases,

the approximate approach used in refs. 29-31 is sufficiently accurate.

Although this approach was originated for application to wave propagation in

an infinite medium, it is applicable also to plates. In the latter con-

figuration, it has been verified experimentally in several instances. By

comparison with static experimental results, Rose and Tshirschnitz (refer-

ence 92 ) found that it gave good predictions of the in-plane elastic

modulus and in-plane shear modulus. Also Achenbach and Zerbe (ref. 32)

found that it gave a frequency versus wavelength relationship for longi-

tudinal vibration of a laminated beam which was in excellent agreement

with experimental results.

In all of the work mentioned above, all of the individual layers were

isotropic. However, in many cases of increasing importance, at least one

of the sets of layers may be made of composite materials. Some examples

*After completion of this derivation, the work of Chou et al.. (Referencecame to the attention of the authors. In their work, Chou et al. derived.purely elastic equations which are analogous to the complex ones derived here,

92

are as follows:

1. Alternating layers of an isotropic material and an orthotropic

material. Examples: armor plate consisting of alternating layers of a

hard ceramic material (isotropic) and a lossy glass fiber-epoxy matrix

composite (orthotropic); a laminate consisting of alternate layers of high-

modulus orthotropic composite material (such as boron-epoxy or graphite-

epoxy) and low-modulus, high-damping polymer (to increase the damping cap-

acity of the laminate).

2. Alternating layers of two different orthotropic composite materials,

Example: Boron-epoxy (for high stiffness) and glass-epoxy (for low cost).

The lamination scheme may be either parallel ply (unidirectional) or cross

ply.

3. Alternating layers of the same composite material and thickness,

but oriented alternately at 4« and -9, where 0 < 9 < 90°. This is the so-

called angle-ply lamination arrangement, which is very popular in a variety

of aerospace structures.

An original derivation is presented here which is applicable to

determination of both the stiffness and damping of the above three classes

of laminates. It may be considered to be a generalization of the work of

refs. 29-31; necessarily the resulting equations reduce to theirs in the

case when both materials are isotropic.

F2. Analysis

The bases for the present analysis, as well as that of refs. 29-

31, are the following hypotheses:

1. Strains in the plane of the laminations are equal.

93

2. Stresses in the direction normal to lamination planes are equal.

Hypothesis 1 leads to the Voigt upper-bound estimate (reference 93)

of the equivalent macroscopic properties of a two-phase material having

arbitrary geometrical configuration of individual constituents. Except

for the presence of an additional Poisson's ratio effects term, this is

known also as the "rule of mixtures". Hypothesis 2 leads to the correspond-

Reuss lower-bound estimate (reference 94), which is almost identical with

the so-called "inverse rule of mixtures".

Here we consider a medium consisting of repeating alternating

layers denoted by "a" and "b", as shown in figure F-l. The plane of

the laminations is designated as the xy plane and z is the normal to this

plane. Then the two hypotheses mentioned above can be stated mathematically

as follows in contracted notation:

e(3) = e(b> = 6 0=1,2,6) (F-l)

o.(a) = Oi(b) = a. U=3,4,5) (F-2)

where the e. are strain components, the a. are stress components, and

superscripts (a) and (b) refer to layers "a" and "b". Subscripts 1 and 2

refer to normal strain (or normal stress) in the plane of the layers, 3

refers to thickness-normal effects, 4 and 5 refer to thickness shear, and

6 refers to in-plane shear. This notation is consistent with that most

widely used in the field of composite-material mechanics (ref. 4) but

differs from the mixed notation used in the body of this report.

As a consequence of the complex, orthotropic version of Hooke's law

94

and static equilibrium, equations (F-l) and (F-2) imply the following re-

lations :

O. = H(a>o.(aWb)0.(b)J J J

1,2,6) (F-3)

(1-3.4.5) (F-4)

where H and H are the thickness fractions of layers "a" and "b",

respectively. Thus,

(F-5)

The complex, orthotropic version of Hooke's law, alluded to above,

holds for each type of layer as follows:

,<»"a"'

°3

"4

°C5

o\ X

>• =

p(k) =(k) s(k) n n = (k)~Cll °12 C13 ° ° C16

g(k) g(k) =(k) -(k)L12 22 °23 U U C26

-(k) =(k) =(k) n = (k)C13 L23 L33 ° ° C36

o o o c.(k) c.(k) o44 45

o o o cfk) c^k) o^»5 55

s(k) =(k) =(k) =(k)L16 26 ^36 °66

^

el

62

e3

e(k)64

(k)e c5

66

(k=a,b)

(F-6)

-(k)where the C.. are the complex stiffness coefficients.

95

f \al°2

°3

(T

3 .

=

\ >

c ' r ' r ' r ' ' r '11 °12 C13 C13 C16

C1 r ' r ' r ' ' r*°12 C22 °23 C23 C26

C(a) C(a) C(a) 0 r(a)°13 C23 C33 ° C36

c(b) c(b> o c(b) c(b)13 ^23 U L33 °36

•<

r \el

e2

(a) se3

(b)e3

, 66 ,

where

(a)

C!, = H(a) C'

; i,j = 11, 12, 16, 22, 26

• - H(b)r (b>-

j ~ " °ij ;

= 13, 23

13, 23

(F-7)

Combining equations (F-4) and the last two of equations (F-7), we

get the following relations:

e(a)= rc(b) , - H(b)fc(a) -e3 LL33 e3 (L13 13 23 " 23 e2

(b) . ,(a)

(F-8)

-H^CCJ^-C^).,! [H(a>C<b) +H(b> C 33

Substituting equations (F-8) and (F-9) into the first of equations

(F-7), one is led to the following result:

(F-10)

96

where

= H(a)g(a) (b)-(b) £ , = (a) 5(b)- " Cll + H Cll KC (C13 ' C13

- ,

13 S

- _ (a) -(a) . H(b)-(b) - -(a) ?(b) -(a) =(b)C16 = " C16 + " C16 ' Kc(C13 " C13 )(C36 ' °36

Kc

Analogous equations to equations (F-10) - (F-14) can be obtained

readily by interchanging the roles of subscripts 1 and 2.

From the last two of equations (F-7), one gets:

+ (C(a) + C(b))e + C(a) (a) + C(b)

Then substituting equations (F-8) and (F-9) into equation (F-17), one

finds the following result:

°3 = 513 el + S3 62 + 533 £3 + 536e6 (F

where C1_ and C__ are given by equation (F-13) and an analogous equation

and

97

36 (F-20)

Still another set of equations analogous to equations (F-10)-(F-14)

can be obtained by interchanging the roles of subscripts 1 and 6.

As the first step toward determining expressions involving the com-

posite coefficients with subscripts 44, 45, and 55, it is expedient to in-

vert the pertinent equations in set (F-6) , thus arriving at the following

expressions:

(F-21)

f 1

e4

Uk>j> =

" ~Q \ ^/ 0 V *^/S44 S45

r» \ "/ o x "/

_S45 S55 _

•«

f \

°4

°5

where

44

55

55

- C°

(k)

. -(k)' S45

r(k) _ :(k) =(k) x«A - C44 C55 " (C45

(F-22)

Inserting equations (F-21) into equations (F-4), we arrive at the

following expressions:

(F-23)hi.I-.}"\ '

S44 S45

§45 §55—

•h\

1^1V. /

where

AA44 44 44 (F-24)

98

There are three expressions, analogous Co equation (F-24), which are

obtained by merely substituting subscripts 45 and 55, respectively,

for subscript 44 in equation (F-24).

We now have derived expressions for all twenty of the laminate

coefficients which appear in equation (F-23), above, and in the follow-

ing expression:

'11

'12

'13

'16

'12

'22

'23

'26

'13

'23

'33

'36

'16

'26

'36

66

/ \

> (F-25)

The effective density of the laminate is given by the following

expression:

D = (F-26)

99

APPENDIX G

IDENTIFICATION OF INTEGRAL FORMS

Gl. Trigonometric Integrals

The integral forms for three boundary conditions are tabulated in

the following form, where m,k,n,-t. = 1 to 2:

"""Irak

hnl

X2mk

hnl

X3mk

'**

X4mk

hnl

IntegralForm

r1 .= 1 * $ dcyJ urn uk

o

= f $ $ fdpJ un ut,o

piH J «v»*vkda

o

1pJ vn v-f-

0

r1

^ J $um$vkda

0

= f * * .dp.1 un vlo

r1= $ $' dor

J urn uko

Pl= $ t ' . dpJ un vlo

Evaluation for

Simply Supported

0 ; m^k

\ ; n=^,^0

0 ; n^-t

% ; ~»0 ; m^k

0 ; nil

0

0

krr/2; m=k#)

0 ; m^k

nrr/2 ; n^-t-^0

0 ; nil

Boundary Condition

Clamped Edges

0 ; m^k

0 ; nil

Jlmk

hi

Tlmk

Zlnt

0 ; ».kW

0 ; m^k

0 ; n=tj^0

0 ; nil

Listed

Free Edgei

3/2 ; m=k=

1 ; m?*k

3/2 ; n-fc

1 ; nil

Xlmk

Xlnt

X lmk

Iln-t

0 ; m-W

0 ; m^k

0 ; n=t :

0 ; nil

100

IntegralForm

T =5mk

'**•

1 =6m k

Ifin; =

T7mk =

I =

X8mk ^

W

Z9mk "

X9nt -

I10mk"

T10ntS

Illmk=:

W

1P ,

J vm uko

r $ $',dpJ vn u-to

f1* «• daJ um uko

r1§ f .dp

J un u-Co

r1*J vm vk0

p1

J vn v-Co

.1r1 $ 6 daJ um uk

o

f1*' f dJ un u-f,o

F $' J ' . daJ vm vko

P1

1 /?» t d» ' /^ QJ vn v-t

o

r1*' 4 ' .daJ um vk

o

f1 ,1 Xt 1 <!* t JOI *r T Q pJ un v-'.o

r1 -J ijrxm wk

P1

1 $ *P €1PJ ilixn w(^

0 Y

Evaluat ion for Boundary Condition Listed

Simply Supported Clamped Edges Free Edges

krr/2 ; m=k#) I. I/. 4mk 4mk0 ; mfk

nrr/2 ; n=-t#0 I, I, .

0 ; n^-f,

0 I. . I. .4mk 4mk

0 I I

0 I, , I. .4mk 4mk

0 I I

j 2 2mkn /2 ; m=k?k) 2mkn ;m=k^0 2mkn ; i

0 ; nn'k 0 ; mj'k 0 ; m?=k

2 2 2n-f,rr /2 ; n=-t^0 2n-trr ;n^L?Q 2n-trr ;0 ; n^-t 0 ; n£t 0 ; n^-C,

mkTT 12 ; m=k^0 I8mk Igmk

0 ; tn^k

n*t'TT / 2 * n^'tfi^O X *• r\on'O on i.

0 ; n^t/

0 T8mk X8mk

0 I I

0 See G2 for 0clamped case

Jj ; n=<t#) See G2 0

0 ; n#.

101

Evaluation for Boundary Condition Listed• C^/TOB Free Edges

dai!2mk - 0

r^112*1S JJ

- fI-\Amk J .

$• da13mk

O

.1kn/2 ; -*«'«

- r.s.f,

nfl/2 ;

.OOf

/

17tnk -i;- iwm wk

da

o ;

k ;

0 ;

*-Udwn

Lllmk

See G2

See G2

kl3nt

llmk

l3mk

H3mk

Il3ni

J5 ; »

0 ; n

^ ' '

o ;

o

o

102

IntegralForm

r* J 'im*wkdof

19nt

r

_. . = «.' t'.da20mk J wm wk

*' $'dpwn wt

22mk

23mk

24mk

.1=~ J

25mk

Evaluation for Boundary Condition ListedSimply Supported Clamped Edges Free Edges

iSmk

n /,0 ; ntfk

0 J "^

h ; m=

kn/2 ; m=k^0

0 ; m?*k

nn/2 ; n=

kn/2 ;

Q . m

nn/2 ;

C Z (C Z -2)m m m m

C Z (C Z -2)n n^ n n ^

mkn/2;m=k#)

.0 ; m^k

lmk

lmk

103

Integral Evaluation for Boundary Condition Listed

Simply Supported Clamped Edges Free Edges

Io^,. - f *^_*L.,dot 0 !,._,_• I

T = I s> s' ri ft n27nt ~ ' *•<—y-i-»ap

= f * *u.fdP

26mk ,1 >|;xm \jjxk . 4mk 4rak

1

I = I $ $ d^y 0 I L27mk J \lfym dfyk 4mk 4mk

X28mk

I28nt

T29mk

T29n*.

I30mk

X30nt

I31mk

*™.

Z32mk

2_1 mkn /2 ; m=k^0

• = | $ ' $ l d a ^ 0 1" J ilfxm \lixk n ,. omko Y ' 0 ; m^k

.1 ntrr^/2 ; n=t^0= $' $' dp Ignj

O '2

-1 . mkn /2 ; m=k^0=1 4 ' $ ' da IQ 1

JQ ij,ym ^yk Q . m^k »mk

= f $' ft' dp IQ ,-o *xn'*H o . n^. 8«<<

P 1 ( i n

~" J tyxm \(iyk 8mko

~~ J tan iliy^ 8n/-o

1 , \ ; m^kj^O I. ,

1 \lfxm uk n y.O U , uliFK

= 1 $. $ .dp I. .% *'xn ut 0 ; n^ lni

S 1 $um%xkda ft ,, Ilmk

o T 0 ; nij*k

I8mk

hnt

X8mk

l8nl

J8mk

I8n^

•""Imk

W

1lmk

un U/A-I/ _ i,° ; ^' 104

Integral

33mk

* f

34mk

r5 J

36mk

38mk

"39mk

Evaluation for Boundary Condition Listed

Simply Supported Clamped Edges Free Edges

o

,1o ^ym u

.1

kn/2 ;

k 0 ; nrf

nn/2 ;

' docuk

kn/2 ; m=k#)

nn/2 ; n=J,j

4nt

4mk

4mk

105

Integral Evaluation for Boundary Condition ListedForm Simply Supported Clamped Edges

39n-£,

40mk

I40n-t

i

41mk

1 41 rut

Z42mk

:43mk

I43nt

T44mk

W

I55mk

'55n,

I56mk

„! nrr/2 ; n=^0 I. ,- f *• $ dp 4n^

J ten v-f, n /,o * 0 ; ntt

rl kn/2 ; m=k#) Ir , , , j 4mk

^ 1 8 , w , OOtJ \^xm vk ,.o 0 ; m#k

.1 nrr/2 ; n=t?k) I= *, $ ' . d PJ ten v-f, . ,.

o T 0 ; n^-t-

= r1* $ da % ; m=k3t° IlmkJ \jfym vk r\ . M

o u y m*tc

" J0%yn v/, 0 . nft

r1= $' $ da 0 I.

J \kyrn vk 4mk0 Y

f1= $! $ ,dp 0 I. ,J \|(yn v-f, 4n-f,

r1= $ $' da 0 I, ,J \|iytn vk 4mk

r1

= 1 1. $ .dp 0 I.J i|(yn v-o 4n-t

- r1*- *• da mkn2/2; m=^0 lsmk= Jo**™ Uk ° 0 ; m^k

= f , $ ' d g n T T » n ~ 8nf.J ten u-t -. /.o 0 ; nf-f.

pi= $' $' dor 0 I

J \liym uk 8mko

= f $' f dp 0 IJ ij/yn u-c 8n-r.

J tern vk 8mk

Free Ed{

W

4mk

4n-[-

•"•Imk

hrA

4mk

4mk

I8tnk

W

I8mk

I8nt

I8mk

106

Integral Evaluation for Boundary Condition ListedForm

Simply Supported Clamped Edges Free Edges

s f $! $'dp 0J , 8 , ft .tyxn v-C, on*, on*,

mkTT2/2 ;

n-f,TT2/2

0 ;

.1

" J $iyn

G2 . Combination Trigonometric-Beam Type Integrals

These integrals are related to Illmk>Illnr I13mk. and I13n^ for

clamped and free edges of the plate mentioned in Appendix Gl. Therefore,

these integrals were evaluated and are listed below:

All Edges Clamped.

r1!,,,= *, $ . doJ,,, , .llmk J tyxm wk

(Zk)2 + (2nm)2\Z sinh 1. sin2mn-2mTT cosh Z, cos 2mn + 2mn\L k k k J

fcos[2mn + Zk]-l cos[2mTT -I 2[2mTi + Z. ] + 2[2mrr -

Ck f 1r < Z. cosh Z. sin 2mn - 2nm sinh Z, cos 2nm,>(Zj2

+(2mTT)2 l k k k JK

^ sinL2inTT~Z, J » x u - *.u»u • *-, j -.:k 1 2f2mTT - Z ] " 2[2mTT + Z ] J

K K

I is analogous to I,, . with the following substitutions:lint

107

m •*-»• n , k •*-»• f , a

r1

2 + ,_ .2 Zk COSh \+ (2nm)

2mn sinh Z. cos

ZL. C!k k

(Zk)2 + (2mTT)2 k

- «~ W 0 4. IU 11 I I l-i. I f\r f\ T : vTT T^

k J k I 2[2mTT - Zk] 2[2mrr + Zk]

•i Z, sinh Z, sin 2mn - 2mn cosh Z. cos 2m-rr + 2mrrfL k k k )

rcos[2nm + zkl~1 cos[2mTT - Z ]-l

Zk Ck I 2r2mTT + Z, ] + 2[2mTT - Z, ] J

I,_ . is analogous to I,_ with the fol lowing substi tut ions:1 4~' 1jmk

m-»-»-n , k «-*- / , <y

108

APPENDIX H

EVALUATION OF EXPERIMENTAL METHODS USED TO DETERMINE MATERIAL

DAMPING IN COMPOSITE MATERIALS

HI. Specimens and Experimental Techniques

The following experimental techniques and specimen types have been

used to determine material damping by experimental means (references

48, 79):

1. Decay of free vibration:

a. Torsional pendulum

*b. Axially vibrating bar (reference 95)

c. Beam*

(1) Free-free (reference 96)

(2) Cantilever (references 97, 98)

2. Resonant response:

*a. Torsional (reference 99)

b. Axial

c. Beam

(1) Free-free (references 99, 100)

*(2) Cantilever (references 101-104)

*Apparently only these methods have been applied to measurement of damping

in composite materials; each is discussed briefly in succeeding paragraphs.

109

d. Cubic block£.

e. Plate (reference 13)

*f. Shell (reference 105)

*3. Rota ting-beam deflection (reference 106)

4. Composite oscillator

5. Ultrasonic methods

6. Thermal methods

Pottinger (reference 95) measured the temporal decay of axial vibrations

of bars (Type Ib, above) of glass fiber-epoxy and boron fiber-aluminum com-

posites in the frequency range of 1 kHz to 100 kHz.

Among the earliest uses of free vibration to determine the logarithmic

decrement of a composite material were the free-free beam experiments re-

ported by Bert et al. (reference 96). The specimens were sandwich beams with

glass-epoxy facings and hexagonal-cell honeycomb cores of either aluminum or

glass-phenolic. Good correlation was obtained between the measured values

of 6 and those predicted by an energy analysis of a Timoshenko beam, which

includes thickness-shear flexibility and rotatory inertia. However, the

complexity of the analysis prevents explicit determination of the 6's of the

facings and core.

Later Schultz and Tsai (references 97, 98) used free flexural vibration

of very thin cantilever beams to determine 6 for glass-epoxy in two con-

figurations: (1) unidirectional with the fibers at an arbitrary orientation

9 with respect to the longitudinal axis of the beam, and (2) symmetrically

laminated quasi-isotropic layups (layer orientations of 0 , -60 , 60 ,

-60°, 0° and of 0°, 90°, 45°, -45°, -45°, 45°, 90°, 0°). In the 9 * 0°,

90° case, the coupling between bending and twisting significantly in-

validated the simple flexural theory used in the data reduction.

110

Adams et al. (reference 99) used torsional and flexural resonant

response to determine the damping of glass fiber-epoxy and carbon

fiber-epoxy. The magnetic-coil driver was located at the one end

of the test bar to excite torsion, Type 2a, and at the center to

excite flexure,Type 2c(l). Similar tests were conducted by Wells

et al. (reference 100) on graphite-epoxy.

Cantilever beams, Type 2c(2), were used by Keer and Lazan (reference

101), Gustafson et al. (reference 102), Mazza et al. (reference 103),

and Tauchert and Moon (reference 104). It is noted that Keer and Lazan

used sandwich-type beams with glass reinforced plastic facings and core,

and determined the resonant energy dissipated per cycle as the measure

of damping, and found it to be proportional approximately to the square

of the stress amplitude, i.e. Kimball-Lovell behavior (see Appendix B).

Clary (ref. 13) conducted resonant response tests on long free-edge

plates (Type 2e) made of unidirectional boron fiber-epoxy. He used

the modified Kennedy-Pancu method of data reduction, and studied the

effect of fiber orientation. The analytical results of the present

study are compared with his experimental results in Section 5.3.

Bert and Ray (reference 105) carried out resonant response measure-

ments on a free-edge, circular, truncated conical shell (Type 2f) with

an aluminum honeycomb core and glass fiber-epoxy facings. They used

the original Kennedy-Pancu data reduction method.

Richter (reference 106) used the rotating-beam deflection technique

(Type 3) to determine the damping characteristics of glass fiber-epoxy

at low frequency (0.01 to 1.67 Hz).

It is apparent that the most popular techniques that have been used

111

in connection with measurement of composite-material damping are the

free-vibration decay and resonant-response methods. Differences in re-

sults obtained by these two methods have been studied analytically by Parke

(reference 73), using a standard linear solid, and by Heller and Nederveen

(reference 107), using a generalized Maxwell model.

H2. Excitation and Data-Reduction Techniques for Modal Resonant

Response of Complicated Structures

The experimental and data-reduction techniques for determining damping

from free-vibration decay are rather straight forward. In contrast, a

great variety of techniques are in use for modal response at resonance,

especially in regard to data reduction.

One approach is to use multiple shakers located at various locations

on the structure and having controlled force amplitudes and phase re-

lationships. This approach was origated by Lewis and Wrisley (reference

108) and has been used and extended by Fraeijs de Veubeke (reference 109),

Asher (references 110,lll),Traill-Nash et al (references 112 ,113) , Hawkins

et al (references 114,115), and de Vries (reference 116). The major dis-

advantage of this approach is the complexity and expense, in time and cost,

of installing multiple shakers.

Another approach is to use a single excitation, even when the structure

is complicated. In conjunction with this method, there are a variety of

resonance-determination methods; these are discussed in the paragraphs which

follow. Comparative critical evaluations of a number of these methods

have been presented by Bishop and Gladwell (reference 117) , Pendered and

Bishop (reference 41) , and Pendered (reference 118) .

112

Peak-Amplitude Method. - In this simple, classical method, resonance

is defined very simply to occur when the amplitude response reaches a

peak. The major disadvantage of this method is that it is limited to

lightly damped systems without closely spaced frequencies. The reason for

this is that both of two closely-spaced-frequency modes may contribute to

the amplitude at an intermediate frequency resulting in an indication of

only one mode (a pseudo mode, of course). In an analytical study of a

typical system with two natural frequencies, closely spaced, Turner

(reference 119) showed that the peak-amplitude method results in a 1307»

error in determination of the resonant amplitude.

In general, there is no direct means of determining the modal damp-

ing, i.e. the magnitude of damping associated with various vibrational

modes. However, it can be determined from the response at the anti-

resonant frequencies, using the equations derived by Brann et al (refer-

ence 120). Also, for the special case of a base-excited system, the ratio

of the tip-to-base amplitude to the base amplitude is related to the

damping, as was shown in references 121,122.

Peak-Quadrature-Component Method. - This method was originated by

Stahle and Forlifer (reference 123) in 1958. In this method, resonance is

defined to occur when the quadrature component (90° out of phase with the

excitation) of the response peaks in either a positive or negative dir-

ection. Damping is determined from the in-phase-component peaks which

occur at a frequency below resonance and another frequency above re-

sonance. Applications of the method are discussed in references 124-126.

Quadrature-Response Method. - In this method, resonance is defined to

occur when the in-phase component of the response vanishes. The errors

associated with this method have been discussed by Pendered (ref. 118).

113

Kennedy-Pancu Method and Its Modifications. - This method was origin-

ated by Kennedy and Pancu (reference 87) in 1947. Its basis is the geo-

metry of the theoretical Argand diagram for a single-degree-of-freedom

damped system, which is a circle (see figure H-l). The data-reduction

procedure is to fair a circle through an Argand diagram obtained from

experimental data corresponding to a range of frequencies. The tacit

assumptions inherent in the method are:

1. The system is a lightly damped, linear system.

2. In the vicinity of a particular resonance, the extraneous con-

tributions from the off-resonant modes are either negligible or invariant

with respect to frequency.

3. There is no damping between the normal modes, i.e. the inertia,

damping and stiffness matrices are all diagonal.

Advantages of the method are:

1. It permits resonant frequencies, modal amplitudes, and modal

damping values all to be determined from the Argand plot.

2. It has been demonstrated on a comparative basis that the KP

(Kennedy-Pancu) has better capability in separating closely spaced re-

sonant frequencies.

In the KP method, two ways to determine the resonant frequencies are

possible. One way is to use the frequency associated with the point (on

the faired-in circle) which is most distant from the real axis. The other

way is to use the maximum frequency spacing technique, in which resonance

is defined to occur when the rate of change of the arc length (of the

Argand plot) with respect to frequency attains a local maximum.

In the original Kennedy-Pancu method, the damping ratio was determined

from the half-power points, which are two ends of the diameter (of the

114

Argand circle) which is parallel to the real axis. See equation (B-56) .

Tendered and Bishop (reference 88) introduced an improved method, based

upon the change in phase with respect to frequency, evaluated at re-

sonance. See equation (B-69).

Gladwell (reference 127) proposed a method of determining the true

response peaks and their associated damping ratios, using three points

on the frequency-response curve. However, Pendered and Bishop (ref. 88)

showed that variations of the two side-points caused changes of 1357o

in the damping coefficient of the system that they investigated.

Keller (reference 128). Smart (reference 129), and Pallett (reference

130), discussed improvements in instrumentation used in conjunction with

the KP method. In his analytical investigation of a typical two-degree-

of freedom system with closely spaced natural frequencies, Turner (ref.

119) indicated a 267, error in resonant amplitude determination, which is

a considerable improvement over the 130% error for the peak-amplitude

method. The modal-shape-determination aspects of the KP method were

discussed in reference 131.

The KP method has been applied successfully to a great variety of

vibrating systems, including:

1. Aircraft ground and flight testing (ref. 87)

2. Beam-type structures (ref. 88)

3. Two-degree-of-freedom system (ref. 120)

4. Liquid-propellant launch-vehicle axial vibration (refs. 132,133)

5. Unstiffened stringer-stiffened, and ring-stiffened sandwich cylin-

drical shells( refs. 103,130,134,135).

6. Sandwich conical shell with composite-material facings (refs. 102-104)

115

7. Composite-material plates (ref. 13).

The last three categories listed above are particularly useful ap-

plications of the mode-separating capability of the KP method, since they

often have numerous closely spaced natural frequencies. Pendered and Bishop

(reference 136) used the KP method in connection with determination of the

dynamic characteristics of a sub-system from resonance test results on

a complete system consisting of two sub-systems.

f

Woodcock (reference137) extended the KP method by providing for any

arbitrary amount of damping of the classical viscous type and by

making no assumptions about the form of the damping, stiffness, and in-

ertia matrices. However, as pointed out by Nissim (reference 138), it

is necessary that the inertia matrix be known a .priori in order to deter-

mine experimentally the complete dynamic description of the system. (It

is noted here that the inertia matrix could be determined experimentally,

at the cost of additional tests, by the displaced-frequency method, refer-

ence 139) . Nissim went on to present a set of data-reduction equations

with which the disadvantages of ref. 138 are eliminated. It should be

pointed out that apparently no actual applications of the methods of

refs. 137 and 138 have been documented so far.

H3. New Equations for Applying Two Different Versions of the Kennedy-

Pancu Method to Two More Realistic Classes of Solids

From linear vibration theory, it is well known that the largest value

of the damping ratio £ for which free vibrations can occur is £=£ =1;

at higher values of f,, the motion is nonperiodic. For a standard linear

solid, Zener (reference 140) showed that the critical loss tangent is 53 ,

which corresponds to approximately 1.183 for g . (This compares with a

116

value of 2.00 for g of a Kelvin-Volgt or Kimball-Lovell solid, since

equation (B-65) is assumed to hold for such materials). Parks (ref.

73 showed the error resulting from the use of equation (B-75) for a

standard linear solid.

As mentioned previously in the preceding section, in applying

the Kennedy-Pancu method, it is tacitly assumed that the inertia, damping

and stiffness matrices are all diagonal. Although this assumption may be

satisfied in the case of a simple structure made of one material, it is

certainly not justified in the case of a laminated composite-material

structure. However, if the damping is sufficiently small that it does

not affect the modal shapes (although, of course, it affects the modal

amplitudes) and the intermodal damping coupling is negligible, then the

KP method should still be sufficiently accurate to justify its use

for engineering purposes.

It was mentioned in Section B3 that, in order for two half-power

points to exist for a Kimball-Lovell material, the damping ratio £

must be less than/"2/2. However, when the damping is greater than this

value, one half-power point (denoted as uu) still exists. Thus, the

method can be modified to accommodate this by using equation (B-55) re-

written as follows:

C = (1/2) [(uu /uu )2 - 1 ] ' (H-l)L n

Just as the modification of the original KP method as described above,

equation (H-l), permits its use regardless of the amount of damping, other

appropriate equations can be derived to extend the use of the method to

linear systems composed of materials represented by other damping models.

117

Here we present original equations for two cases: the standard linear

solid (or first-degree hereditary mode 1) and the Biot model. Since

these models contain two parameters rather than one as in the cases of

viscous and Kimball-Lovell damping, more experimental data will be

necessary, of course.

Standard Linear Solid (or First-Degree Hereditary Model). -

Volterra (ref. 83) presented an analysis of the sinusoidally forced

vibration of a single-degree-of-freedom system exhibiting first-de-

gree hereditary damping, which is equivalent to a standard linear

solid. The equation of motion can be written in the present notation

as follows:

•£

mu + ku + h I e 1 [ d u ( T ) / d f ] d T = F sin out (H-2)J o

or

mil 4o/ tnii + (k+h)ii +0. ku = F (uu cos ULit + c^sin uut) (H-3)

The steady-state-response solution of equation (H-3) is of the

form:

u = u sin (ait - en) (H-4)o r

where

u H (F An) {[a2 u;2- (a2. -H2-^2-^]*+[(*/aT)2 |1/2

o o L n l n i J

f 2 2 2 2 2 2 2 2 2 1 - 1' \a, (it - uu ) + audir-aT-HV \ (H-5)L i n n J

f U2 r 2 2 . 2 2 2. 2 4,-l \cp= arctan ^^H oj [^ ^n - (a^H -oi^uo -uu J | .

118

2 2H = h/m , ou 3= k/ro

n

Equation (H-5) can be written in dimensionless form as follows:

[ - ? ? 2 2 2 - 2 2 " ! - ]« (i - a ) + rrco-i-irr ) fe-7)

where

a H Qf /u, , H = H/UJ .I n n

At resonance defined by U) =* ua (0=1), the resonant magnification

factor is:

-- 2 1/2 -1KMF-[l+(aH) I1' /IT (H-8)

At the half-power points

HPMF » RMF//2 (H-9)

(

Combining equations (H-7, H-8, H-9), we obtain the following

result:

where

K ? [l+(a H )2] (2 H6)"1

119

2Unfortunately, equation (H-10) is quartic in H. and thus is very

unwieldy for practical use.

To develop equations for the Tendered improvement of the KP method

for a standard linear solid, we diffrentiate equation (H-6) with re-

spect to time, obtaining the following result:

O O f O O O O O 0 / 1 O / O ^ 1

dcp/duu = a1 h uu | [a uu - (a -h -uu )uu -uu ] + a b (JJ [ (H-ll)

At resonance defined by OJ=(U and denoted by subscript R, we can

simplify equation (H-ll) as follows:

(dcp/dou)D = f [1 + (uu /a)2](u I"1

K L n n j

or

a = uu I [uu (dcp/duu) ] - 1 [n l» n R ;-1/2

(H-12)

It is interesting to note that at resonance, the parameter h drops

out, so that 01 can be determined directly from equation (H-12). To

determine h, it is necessary to measure dcp/duu at some other frequency

(say uu1) and then use equation (H-ll), with a known from equation (H-12).

The second frequency uu1 should not be too close to uu to avoid inaccuracy.

However, it should not be too far from oj that the MF has dropped down to

such a low value that signal-to-noise-ratio difficulties develop.

Biot Solid. - Caughey (ref. 60) presented an analysis of the sin-

usoidally forced vibration of a single-degree-of-freedom system with

Biot damping. In the present notation, the equation of motion is:

120

rc

mu + ku -g tk J Ei [-e(t-r)] (du/df) dT = J sin out (H-13)o

where g and e are parameters of the model.

The steady-state-response solution of equation (H-13) is of the

same form as equation (H-4) , where here

- .02]2+[g1arctan(.0/u)]2}^

cp s arctan (ir/2)gl fl+Cg/2) In (l/|j) - H] - (H-15)

where

, U sn n

Equation (H-14) may be rewritten in terms of the magnification

factor as follows:

C i' 2 2 91 1/7MF = |Cl+g1^n/l+(Q/u)2 -n ] + L^a rc t an (Q/u) ] j- ' (R_16)

At resonance defined by ou = ou (i.e. f) = 1), the resonant magnifi-

cation factor is:

RMF = g" [(^nl-M-2) + (arctan (H-17)

It is noted that the RMF defined in this way is not the peak MF, but it

is very close to it in practical systems. Also, t is emphasized that

the RMF is a function of both parameters, g and u. Thus, data from some

other frequency is required. At the half-power points (subscript hp)

121

defined by HPMF = RMF//2 , the following relation must hold:

)2 ]2 + [g^rctan (Oh /u) ]2 = 2/(RMF)2

(H-18)

Using the necessary experimental data, equations (H-17) and

(H-18) can be used to determine the Biot material parameters g and

U.

To derive Pendered type K? relations, we take the derivative of

equation (H-15) with respect to time, with the following result:

dcp/du {[l-02+(gl /2Kn u'9 91

+ (TT/2)^gJj

-1(H-19)

At resonance defined by 0 = 1 and denoted by subscript R, we

can simplify equation (H-19) to the following result:

(dcp/du,)D = -K. (H-20)

Since equation (H-20) contains both parameters (g and u), it is

necessary to measure dcp/du; at some other frequency (say Q1) and then

use equations (H-19) and (H-20) to solve for the two parameters.

122

APPENDIX I

DISCUSSION ON SYMMETRY OF THE ARRAY

OF CONSTITUTIVE COEFFICIENTS

In the analyses made in the body of this report, we have assumed

that the arrays of both the elastic coefficients and the damping coef-

ficients are symmetric, i.e.

In the present appendix, we discuss both classical and modern think-

ing, as well as experimental results which are pertinent to this topic

of symmetry of the constitutive-coefficient arrays. In recent years, the

validity of the symmetry hypothesis has been questioned for a wide

variety of materials such as soil, geological formations, laminated wood,

fabrics subjected to membrane loads, and certain composite materials

(references 141-144).

II. Elastic Coefficients

More than a century ago, there was considerable controversy regarding

the symmetry of the stiffness matrix (or the compliance matrix) of a

perfectly elastic material. About a century ago, the argument was supposedly

resolved by the brilliant mathematical analysis due to George Green and

123

the experimental work of Woldemar Voigt; see reference 145. Although

Green's analysis was purely mathematical, its importance to modern energy

methods of static and dynamic stress analysis was recognized by Love

(reference 146) , who stated that symmetry of the elastic coefficient array

is a necessary condition for the existence of the strain energy function.

Voigt verified that symmetry did hold, within experimental accuracy, for

the wide variety of single crystals which he investigated. Thus, this

hypothesis became well established in anisotropic elasticity theory and

it was tacitly assumed to hold for all materials.

Incidentally symmetry of the compliance matrix array requires that

the following so-called reciprocal relationship must hold among four of

the engineering elastic properties:

V., /E = v, . /E (k,-t=l,2,3; no sum) (1-1)

where the E's are Young's moduli and the v's are Poisson's ratios.

Recently Alley and Faison (ref. 143) clearly demonstrated experimentally

that equation (1-1) does not hold for fabrics subjected to biaxial load-

ings. They attributed this result to fiber friction, which is a noncon-

servative process. Table III lists some filamentary-composite-material

test values for which eq. (1-1) does not hold. The viscosity of the epoxy

matrix may have been the nonconservative process operative in the case

of the glass-epoxy and boron-epoxy composites; see Section 12 of this

Appendix. Also, the glass was in fabric form, so fabric friction could

have played a part. Furthermore, in the case of the boron-epoxy composite,

the minor Poisson's ratio is so very small that it is difficult to measure

124

with a high degree of confidence and experimental scatter effects become

highly magnified. However, none of these explanations account for the

case of graphite-graphite composite. It does not creep at the test

temperature (room temperature); the fibers were filament wound, not

in fabric form; and the minor Poisson's ratio is large enough to be

measured accurately (especially since .strain-gage transverse sensitivity

was provided for in the data reduction). Thus, so far, there has not

been a satisfactory explanation for this anomaly.

12. Viscoelastic Materials

For viscoelastic materials which are homogeneous and anisotropic

on a macroscopic basis, Rogers and Pipkin (ref. 141) claimed that there

are no thermodynamic bases which require symmetry of the array of con-

stitutive coefficients. Thus, they indicated that for such materials,

symmetry can be established by experiment only. For composite materials

having a viscoelastic (epoxy resin) matrix, some experimental data

suggest that symmetry may not hold in the case of reinforcement by

glass fibers and boron fibers (see table III). However, other experi-

mental data on a viscoelastic composite (nylon-fiber-reinforced rubber)

suggest that symmetry does hold.

In view of the lack of a definite proof regarding symmetry of a

viscoelastic material, symmetry is assumed to hold in the present in-

vestigation (see hypothesis H6, Section 2.1).

125

APPENDIX J

COMPUTER PROGRAM DOCUMENTATION

The program described in this appendix was programmed to ac-

complish the following three computations:

1. Calculate the shear factor K for laminates, using Jourawski

static shear theory.

2. Calculate the lowest eigenvalue for a simply supported laminated

plate without damping.

3. Calculate the amplitude frequency response and modified

Kennedy-Pancu frequency response and damping data for a free-

edge anisotropic plate with material damping.

Computation 1 was accomplished by using an explicit algebraic expression.

Computation 2 was performed by using IBM System/360 Scientific Subroutine

Packages NROOT and EIGEN. Computation 3 was performed by Package SMIQ.

A complete description of the variables, operations, etc. may be found in

IBM Manual 360A-CM-03X, version III, for the subroutines NROOT, EIGEN and

SMIQ.

The program was written in FORTRAN IV language as prescribed in IBM

System Reference Library Form C-28-6274-3.

The input-data deck was set up as follows.:

Computation 1 -

126

(a) Thickness of each layer (lower and upper limit)

(b) Elastic and shear moduli

Computation 2 -

(a) Plate geometryi

(b) Lamination geometry (specially orthotropic)

(c) Moduli and Poisson's ratio data for each ply

(d) Density for each ply

(e) Shear factor (as calculated in Computation 1)

Computation 3 -

(a) Young's and shear moduli for each layer

(b) Poisson's ratios for each layer

(c) Bending and twisting stiffnesses for each layer

(d) Loss tangents corresponding to moduli, Poisson's ratios, and

stiffnesses for each layer

(e) Plate geometry

(f) Lamination geometry, including angle of orientation for each

layer

(g) Density of each layer

(h) Shear factor (as calculated in Computation 1)

(i) Mode numbers of the assumed modes.

A complete listing of the computer program is presented at the end

of this report.

127

REFERENCES

1. Engler, E.E.; and Cataldo, C.E.: Design and Test of Advanced Structural

Components and Assemblies. NASA Space Shuttle Technology Conference,

vol. II, NASA TM X-2273, Apr. 1971, pp. 527-583.

2. Ashton, J.E. ; and Whitney, J.M.: Theory of Laminated Plates. Technomic

Publishing Co., Inc., 1970.

3. Ojalvo, I.U.; and Areas, N.: Approximate Analysis and Dynamic Tests for

a Thermal Protection System Panel. NASA Space Shuttle Technology

Conference, vol. Ill, NASA TMX-2274, Apr. 1971, pp. 49-93.

4. Ashton, J.E.; Halpin, J.C.; and Petit, P.H.: Primer on Composite Materials:

Analysis. Technomic Publishing Co., Inc., 1969.

5. Tsai, S.W.: Structural Behavior of Composite Materials. NASA CR-71,

July 1964.

6. Chambers, R.E.; and McGarry, F.J.: Shear Effects in Glass Fiber Re-

inforced Plastics Laminates. ASTM Bull., no. 238, May 1959, pp. 38-

41.

7. Khischenko, Yu. M. : Effect of Shear on the Modulus of Elasticity of

Specimens of Glas-Fiber Reinforced Plastics Tested in Transverse

Bending. Indust. Lab., vol. 30, no. 6, June 1964, pp. 937-939.

8. Tarnopol'skii, Yu. .; Roze, A.V.; and Polyakov, V.A.: Shear Effects

During Bending of Oriented Glass Reinforced Plastics. Polymer Mechanics,

128

vol. 1, no. 2, Mar.-Apr. 1965, pp. 31-37.

9. Yu., Y.-Y.: Simple Thickness-Shear Modes of Vibration of Infinite

Sandwich Plates. J. Appl. Mech., vol. 26, no. 4, Dec. 1959, pp.

679-681.

10. Ross, D.; Ungar, E.E.; and Kerwin, E.M., Jr.: Damping of Plate

Flexural Vibrations by Means of Viscoelastic Laminae. Structural

Damping, J.E. Ruzicka, ed., Amer. Soc. Mech. Engrs., 1959, pp.

49-87.

11. Ruzicka, J.E.; Derby, T.F.; Schubert, D.W.; and Pepi, J.S.: Damp-

ing of Structural Composites with Viscoelastic Shear-Damping

Mechanisms. NASA CR-742, Mar. 1967.

12. Derby, T.F.; and Ruzicka, J.E.: Loss Factor and Resonant Frequency

of Viscoelastic Shear-Damped Structural Composites. NASA CR-1269,

Feb. 1969.

13. Clary, R.R.: Vibration Characteristics of Unidirectional Filamentary

Composite Material Panels. Composite Materials: Testing and Design

(Second Conference), Amer. Soc. Testing & Matls., Spec. Tech. Publ.

497, 1972, pp. 1*15- 38.

14. Pister, K.S.: Flexural Vibration of Thin Laminated Plates. J. Acoust.

Soc. Amer., vol. 31, no. 2, Feb. 1959, pp. 233-234.

15. Stavsky, Y. : Thermoelastic Vibrations of Heterogeneous Membranes and

Inextensional Plates. A1AA J., vol. 1, no. 3, Mar. 1963, pp. 722-723.

129

16. Ashton, J .E. : Analysis of Anisotropic Plates. J. Composite Ma t l s . ,

vol. 3, no. 1, Jan. 1969, pp. 148-165.

17. Hikami, Y.: Transverse Vibrations of Laminated Orthotropic Plates.

Rept. No. 32, Div. of Solid Mech., Structures, & Mech. Design,

Case Western Reserve Univ., Apr. 1969.

18. Ashton, J.E.: Natural Modes of Free-Free Anisotropic Plates. Shock

& Vib. Bull., Bull. 39, Pt. 4, U.S. Dept. Defense, Apr. 1969, pp. 93-97.

19. Whitney, J.M.; and Leissa, A.W.: Analysis of Heterogeneous Anisotropic

Plates. J. Appl. Mech., vol. 36, no. 2, June 1969, pp. 261-266.

20. Whitney, J.M.; and Leissa, A.W.: Analysis of a Simply Supported

Laminated Anisotropic Rectangular Plate. AIAA J., vol. 8, no. 1,

Jan. 1970, pp. 28-33.

21. Ashton, J.E.; and Anderson, J.D.: The Natural Modes of Vibration

of Boron-Epoxy Plates. Shock & Vib. Bull., Bull. 39, Pt. 4, U.S.

Dept. Defense, Apr. 1969, pp. 81-91.

22. Bert, C.W.; and Mayberry, B.L.: Free Vibrations of Unsymmetrically

Laminated Anisotropic Plates with Clamped Edges. J. Composite

Matls., vol. 3, no. 2, Apr. 1969, pp. 282-293.

23. Ambartsumyan, S.A.: Theory of Anisotropic Plates. Technomic Publish-

ing Co., Inc. , 1970.

24. Whitney, J.M.: The Effect of Transverse Shear Deformation on the

Bending of Laminated Plates. J. Composite Matls., vol. 3, no. 3,

130

July 1969, pp. 534-547.

25. Yang, P.C.; Norris, C.H.; and Stavsky, Y.: Elastic Wave Propagation in

Heterogeneous Plates. Int. J. Solids & Struct., vol. 2, no. 4, Oct.

1966, pp. 665-684.

26. Mindlin, R.D.: Influence of Rotatory Inertia and Shear on Flexural

Motions of Isotropic, Elastic Plates. J. Appl. Mech., vol. 18, no.

1, Mar. 1951, pp. 31-38.

27. Biot, M.A.: Continuum Dynamics of Elastic Plates and Multilayered Solids

Under Initial Stress. J. Math. &Mech., vol. 12, no. 6, Nov. 1963, pp.

793-803.

28. Bolotin, V.V.: Vibration of Layered Elastic Plates. Proc. Vib. Probs.

(Pol. Acad. Sci,.) , vol. 4, no. 4, 1963, pp. 331-345.

29. Postma, G.W.: Wave Propagation in a Stratified Medium. Geophysics, vol.

20, no. 4, Oct. 1955, pp. 780-806.

30. White, J.E.; and Angona, F.A.: Elastic Wave Velocities in Laminated

Media. J. Acoust. Soc. Amer., vol. 27, no. 2, Mar. 1955, pp. 310-317.

31. Rytov, S.M.: Acoustical Properties of a Thinly Laminated Medium.

Soy. Phys.-Acoust., vol. 2, no. 1, Jan. 1956, pp. 68-80.

32. Achenbach, J.D.; and Zerbe, T.R.: Flexural Vibrations of Laminated Plate.

J. Eng. Mech. Div., Proc. ASCE, vol. 97, no. EM3, June 1971, pp. 619-628.

33. Hsu, T.M.; and Wang, J.T.: A Theory of Laminated Cylindrical Shells

Consisting of Layers of Orthotropic Laminae. AIAA J., vol. 8, no. 12,

131

Dec. 1970, pp. 2141-2146.

34. Wang, J.T.-S.: Axisymmetric Deformation Theory of Orthotropic

Layered Cylindrical Shells. Developments in Mechanics, vol. 6 (Proci

12th. Midwestern Mech. Conf., Aug. 1971), Univ. of Notre Dame Press,

1971, pp. 787-800.

35. Srinivas, S.; Joga Rao, C.V.; and Rao, A.K.: An Exact Analysis

for Vibration of Simply-Supported Homogeneous and Laminated Thick

Rectangular Plates. J. Sound & Vib. , vol. 12, no. 2, June 1970,

pp. 187-200.

36. Srinivas, S.; Joga Rao, C.V.; and Rao, A.K.: Some Results from an Exact

Analysis of Thick Laminates in Vibration and Buckling. J. Appl.

Mech., vol. 37, no. 3, Sept. 1970, pp. 868-870.

37. Srinivas, S.; and Rao, A.K.: Bending, Vibration and Buckling of

Simply Supported Thick Orthotropic Rectangular Plates and Laminates.

Int. J. Solids & Structures, vol. 6, no. 11, Nov. 1970, pp. 1463-

1481.

38. Tso, F.K.W.; Dong, S.B.; and Nelson, R.B.: Natural Vibrations of

Rectangular Laminated Orthotropic Plates. Developments in Mechanics,

vol. 6 (Proc. 12th. Midwestern Mech. Conf., Aug. 1971), Univ. of

Notre Dame Press, 1971, pp. 891-905.

39. Dong, S.B.: Behavior of Laminated Orthotropic Viscoelastic Plates.

J. Spacecraft & Rkts., vol. 4, no. 10, Oct. 1967, pp. 1385-1388.

40. Timoshenko, S.P.: History of Strength of Materials. McGraw-Hill

132

Book Co., Inc., 1953, p. 141.

41. Timoshenko, S.: On the Correction for Shear of the Differential

Equation for Transverse Vibrations of Prismatic Bars. Phil. Mag.,

ser. 6, vol. 41, 1921, pp. 744-746.

42. Timoshenko, S.: Vibration Problems in Engineering, 3rd. Ed.

D. Van Nostrand Co., Inc., 1955, p. 329.

43. Reissner, E.: The Effect of Transverse-Shear Deformation on the

Bending of Elastic Plates. J. Appl. Mech., vol. 12, no. 1, Mar.

1945, pp. A69-A77.

44. Young, E.; and Felgar, R.P., Jr.: Tables of Characteristic Functions

Representing Normal Modes of Vibration of a Beam. Bulletin No.

4913, Bureau of Engineering Research, University of Texas, Austin,

Tex., July 1, 1949.

45. Wang, J.T.: On the Solution of Plates of Composite Materials. J.

Composite Matls., vol. 3, no. 3, July 1969, pp. 590-592.

46. Bert, C.W.; and Chang, S.: In-Plane, Flexural, Twisting and Thickness-

Shear Coefficients for Stiffness and Damping of a Monolayer Filamentary

Composite. Final Report (Part I) on NASA Research Grant NGR-37-003-055,

School of Aerospace, Mechanical and Nuclear Engineering, University of

Oklahoma, Norman, Okla., Mar. 1972.

47. Ganov, E.V.: Investigation of Bending Stresses in Shingle-Laminated

Glass Reinforced Plastic. Polymer Mech., vol. 1, no. 5, Sept.-Oct.

133

1965, pp. 101-102.

48. Lazan, B.J.: Damping of Materials and Members of Structural Mechanics.

Pergamon Press, 1968.

49. Kimball, A.I..; and Lovell, D.E.: Internal Friction in Solids. Physical

Rev., ser. 2, vol. 30, 1927, pp. 948-959.

50 . Wegel, R.L.; and Walther, H.: Internal Dissipation in Solids for Small

Cyclic Strains. Physics, vol. 6, 1935, pp. 141-157.

51 . Lazan, B.J.: A Study with New Equipment of the Effects of Fatigue

Stress on the Damping Capacity and Elasticity of Mild Steel. Trans.

Am. Soc. Metals, vol. 42, 1950, pp. 499-549.

52 . Bishop, R.E.D.: The Theory of Damping Forces in Vibration Theory.

J. Roy. Aeron. Soc., vol. 59, no. 539, Nov. 1955, pp. 738-742.

53 . Soroka, W.W.: Note on the Relations Between Viscous and Structural Damping

Coefficients. J. Aeron. Sci., vol. 16, no. 7, Jul. 1949, pp. 409-

410, 448.

54. Theodorsen, T.; and Garrick, I.E.: Mechanism of Flutter - a Theoretical

and Experimental Investigation of the Flutter Problem. NACA TR

685, 1940.

55 . Scanlan, R.H.; and Rosenbaum, R. : Introduction to the Study of Air-

craft Vibration and Flutter. Macmillan, 1951; Dover, 1968.

56 . Myklestad, N.O.: The Concept of Complex Damping. J. Appl. Mech.,

vol. 19, no. 3, Sep. 1952, pp. 284-286.

134

57. Lancaster, P.: Free Vibration and Hysteretic Damping. J. Roy.

Aeron. Soc. , vol. 64, no. 592, Apr. 1960, p. 229.

58. Reid, T.J.: Free Vibration and Hysteretic Damping. J. Roy. Aeron.

Soc., vol. 60, no. 544, Apr. 1956, p. 283.

59. Milne, R.D.: A Constructive Theory of Linear Damping. Paper C.4,

Symposium on Structural Dynamics, Loughborough Univ. of Technology,

Longhborough, England, 1970.

60. Caughey, T.K.: Vibration of Dynamic Systems with Linear Hysteretic

Damping (Linear Theory). Proc. 4th. U.S. Nat. Congr. Appl. Mech.,

vol. 1, 1962, pp. 87-97.

61. Paley, R.E.A.C.; and Wiener, N.: Fourier Transforms in the Complex

Domain. Am. Math. Soc. Colloquium Publicat., vol. 19, 1934.

62. Garcia-Moliner, F.; and Thomson, R.: Linear Response Functions and

the Phenomenological Equations of Internal Friction. J. Appl.

Phys., vol. 37, no. 1, Jan. 1966, pp. 83-89.

63. Fraeijs de Veubeke, B.M. : Influence of Internal Damping on Aircraft

Resonance. AGARD Manual on Elasticity, vol. 1, chap. 3, 1960.

64. Crandall, S.H.: Dynamic Response of Systems with Structural Damping.

Air, Space, and Instruments (C.S. Draper Anniv. Vol.), S. Lees,

ed. McGraw-Hill Book Co., 1963, pp. 183-193.

65. Crandall, S.H.: The Role of Damping in Vibration Theory. J. Sound &«

Vib., vol. 11, no. 1, Jan. 1970, pp. 3-18.

135

66. Pinsker, W.: Structural Damping. J. Aeron. Sci., vol. 16, no. 11,

Nov. 1949, p. 699.

67. Scanlan, R.H.; and Mendelson, A.: Structural Damping. AIAA J. , vol.

1, no. 4, Apr. 1963, pp. 938-939.

68. Naylor, V.D.: Some Fallacies in Modern Damping. J. Sound & Vib.,

vol. 11, no. 2, Feb. 1970, pp. 278-280.

69. Scanlan, R.H.: Linear Damping Models and Causality in Vibrations.

J. Sound &Vib., vol. 13, no. 4, Dec. 1970, pp. 499-509.

70. Bishop, R.E.D.: The Behavior of Damped Linear Systems in Steady

Oscillation. Aeron. Quart., vol. 7, no. 2, May 1956, pp. 156-168.

71. Cunningham, H.J.: In Defense of Modern Damping Theory in Flutter

Analysis. J. Sound & Vib., vol. 14, no. 1, Jan. 1971, pp. 142-144.

72. Bland, D.R.: The Theory of Linear Viscoelasticity. Pergamon Press,

1960, pp. 3-4.

73. Parke, S.: Logarithmic Decrements at High Damping. Brit . J. A p p l .

Phys., vol. 17, no. 2, Feb. 1966, pp. 271-273.

74. Fliigge, W.: Viscoelasticity. Blaisdell Publishing Company, 1967,

p. 14.

75. Hobbs, G.K.: Methods of Treating Damping in Structures. AIAA Paper

71-349, presented at the AIAA/ASME 12th Structures, Structural

Dynamics and Materials Conference, Anaheim, Calif., Apr. 19-21, 1971,

136

76. Huang, T.C.; and Huang, C.C.: Free Vibrations of Viscoelastic

Timoshenko Beams. J. Appl. Mech., vol. 38, no. 2, June 1971,

pp. 515-521.

77. Granick, N. and Stern, J.E.: Material Damping of Aluminum

by a Resonance-Dwell Technique. NASA TN D-2893, Aug. 1965.

78. Granick, N.; and Stern, J.E.: Material Damping of Aluminum by

Resonance-Dwell Technique. Shock & Vib. Bull., Bull. 34, Pt. 5,

U.S. Dept. Defense, Feb. 1965, pp. 177-195.

79. Gustafson, A.J.; Mazza, L.T.; Rodgers, R.L.; and Mcllwean, E.A.:

Development of Test Methods for Measuring Damping of Fiber-

Reinforced Materials. Rept. USAAVLABS TR 70-42, U.S. Army

Aviation Materiel Laboratories, Ft. Eustis, Va., June 1970

(AD-873990).

80. Biot, M.A.: Linear Thermodynamics and the Mechanics of Solids.

Proc. 3rd. U.S. Nat. Congr. Appl. Mech., 1958, pp. 1-18.

81. Neubert, H.K.P.: A Simple Model Representing Internal Damping in

Solid Materials. Aeron. Quart., vol. 14, no. 2, May 1963, pp.

187-210.

82. Boltzmann, L.: Zur Theorie der elastische Nachwirkung. Annalen

der Physik und Chemie, suppl. 7, 1876, pp. 624-654.

83. Volterra, E.: Vibrations of Elastic Systems Having Hereditary

Characteristics. J. Appl. Mech., vol. 17, no.4, Dec. 1950, pp.

363-371.

137

84. Pisarenko, G.S.: Vibrations of Elastic Systems Taking Account of

Energy Dissipation in the Material. Kiev, 1955; Engl. transl.,

WADD TR-60-582, Wright Air Development Div., Feb. 1962 (AD-274743).

85. Rosenblueth, E.; and Herrera, I.: On a Kind of Hysteretic Damping.

J. Eng. Mech. Div., Proc. ASCE, vol. 90, no. EM4, Aug. 1964, pp.

37-48.

86. Chang, C.S.; and Bieber, R.E.: Synthesis of Structural Damping.

AIAA J., vol. 6, no. 4, Apr. 1968, pp. 718-719.

87. Kennedy, C.C.; and Pancu, C.D.P.: Use of Vectors in Vibration

Measurement and Analysis. J. Aeron. Sci., vol. 14, no. 11, Nov.

1947, pp. 603-625.

88. Pendered, J.W.; and Bishop, R.E.D.: A Critical Introduction to

Some Industrial Resonance Testing Techniques. J. Mech. Eng.

Sci., vol. 5, no. 4, Dec. 1963, pp. 345-367.

89. Kolsky, H.: Stress Waves in Solids. Oxford Univ. Press, 1953;

Dover, 1963.

90. Bishop, R.E.D.: The General Theory of "Hysteretic Damping". Aeron.

Quart., vol. 7, no. 1, Feb. 1956, pp. 60-70.

91. Meirovitch, L. : Analytical Methods in Vibrations. Macmillan, 1967, p. 40.

92. Rose, J.L.; and Tshirschnitz, R.: Static Material Constants for

a Layered Composite Material. Paper No. 1845A, Spring Meeting,

138

Soc. for Exper. Stress Anal., Salt Lake City, Utah, May 18-21, 1971.

93. Voigt, W.: Lehrbuch der Kristallphysik. B.C. Teubner, Leipzig, Germany,

1928, pp. 738-741.

94. Reuss, A.: Berechnung der Fliessgrenze von Mischkristalien auf Grund der

Plastizitatsbedingung fur Einkristalle. Zeits. f. ang. Math. u. Mech.,

vol. 9, no. 1, Feb. 1929, pp. 48-58.

95. Pottinger, M.G.: Material Damping of Glass Fiber-Epoxy and Boron Fiber-

Aluminum Composites. Rept. ARL 70-0237, Aerospace Research Lab-

oratories, Wright-Patterson Air Force Base, Ohio, Oct. 1970 (AD-721191).

96. Bert, C.W.; Wilkins, D.J., Jr.; and Crisman, W.C.: Damping in Sandwich

Beams with Shear-Flexible Cores. J. Eng. Industry, Trans. ASME,

vol. 89B, no. 4, Nov. 1967, pp. 662-670.

97. Schultz, A.B.; and Tsai, S.W.: Dynamic Moduli and Damping Ratios in Fiber-

Reinforced Composites. J. Composite Matls., vol. 2, no. 3, July 1968,

pp. 368-379.

98. Schultz, A.B.; and Tsai, S.W.: Measurements of Complex Dynamic Moduli for

Laminated Fiber-Reinforced Composites. J. Composite Matls., vol. 3, no.

3, July 1969, pp. 434-443.

99. Adams, R.D.; Fox, M.A.O.; Floord, R.J.L.; Friend, R.J.; and Hewitt, R.L.:

The Dynamic Properties of Unidirectional Carbon and Glass Fiber Re-

inforced Plastics in Torsion and Flexure. J. Composite Matls., vol. 3,

no. 4, Oct. 1969, pp. 594-603.

100. Wells, H.; Colclough, W.J.; and Goggin, P.R.: Some Mechanical Properties

139

of Carbon Fibre Composites. Proc. 24th. Ann. .Tech. & Mgt. Conf.,

Reinf. Plastics/Composites Div., Soc. Plastics Industry, Inc.,

1969, sect. 2-C.

102. Gustafson, A.J.; Mazza, L.T.; Rodgers, R.L.; and Mcllwean, E.H.:

Development of Test Methods for Measuring Damping of Fiber-Re-

inforced Materials. Rept. USAAVLABS TR 70-42, U.S. Army Aviation

Materiel Laboratories, Ft. Eustis, Va., 1970 (AD-873990).

103. Mazza, L.T.; Paxson, E.B.; and Rodgers, R.L.: Measurement of

Damping Coefficients and Dynamic Modulus of Fiber Composites. Rept.

USAAVLABS-TN-2, U.S. Army Aviation Materiel Laboratories, Ft. Eustis,

Va., 1971 (AD-869025).

104. Tauchert, T.R.; and Moon, F.C.: Propagation of Stress Waves in Fiber-

Reinforced Composite Rods. AIAA J., vol. 9, no. 8, Aug. 1971, pp.

1492-1498.

105. Bert, C.W.; and Ray, J.D.: Vibrations of Orthotropic Sandwich Conical

Shells with Free Edges. Int. J. Mech. Sci., vol. 11, no. 9, Sept.

1969, pp. 767-779.

106. Richter, H.P.H.: Photographic Method for Measuring Material Damp-

ing and Dynamic Young's Modulus at Low Frequencies Applied to

a Fiberglass Reinforced Resin Structure. Proc. 18th.Ann. Tech.

& Mgt. Conf., Reinf. Plastics Div., Soc. Plastics Industry, Inc.,

1963, sect. 4-D.

140

107. Heller, R.A.; and Nederveen, C.J.: Comparison of Complex Moduli Ob-

tained from Forced and Free Damped Oscillations. Trans. Soc. Rheology,

vol. 11, no. 1, 1967, pp. 113-123.

108. Lewis, A.C.; and Wrisley, D.L.: A System for the Excitation of Pure

Modes of Complex Structures. J. Aeron. Sci., vol. 17, no. 11, Nov.

1950, pp. 705-722.

109. Fraeijs de Veubeke, B.M.: A Variational Approach to Pure Mode Excitation

Based on Characteristic Phase Lag Theory. AGARD Rept. 39, Advisory

Group for Aeron. Res. & Dev., North Atlantic Treaty Org., Apr. 1956.

110. Asher, G.W.: A Method of Normal Mode Excitation Utilizing Admittance

Measurements. Proc. Nat. Specialists Meeting on Dynamics & Aeroelasti-

city, Ft. Worth, Tex., Nov. 6-7, 1958; Inst. of Aeron. Sci., 1959, pp.

69-76.

111. Asher, G.W.: A Note on the Effective Degrees of Freedom of a Vibrating

Structure. AIAA J., vol. 5, no. 4, Apr. 1967, pp. 822-824.

112. Traill-Nash, R.W.: On the Excitation of Pure Natural Modes in Aircraft

Resonance Testing. J. Aero/Space Sci., vol. 25, no. 12, Dec. 1958, pp.

775-778.

113. Traill-Nash, R.W.; Long, G. ; and Bailey, C.M.: Experimental Determination

of the Complete Dynamical Properties of a Two-Degree-of-Freedom Model

Having Nearly Coincident Natural Frequencies. J. Mech. Eng. Sci., vol.

9, no. 5, Dec. 1967, pp. 402-413.

114. Hawkins, F.J.: An Automatic Shake Testing Technique for Exciting the Normal

141

Modes of Vibration of Complex Structures. AIAA Sympos. on Struct.

Dynamics & Aeroelasticity, Boston, Mass., Aug. 30-Sept. 1, 1965,

pp. 452-464.

115. Hawkins, F.J.; Skingle, C.W.; and Taylor, G.A.: A Multiple-Frequency,

Shake-Testing Technique for Structures with Rapidly-Changing Dynamic

Characteristics. Shock &Vib. Bull., Bull. 35, Pt. 2, U.S. Dept.

Defense, Jan. 1966, pp. 107-116.

116. de Vries, G.: The Principles of Global Tests of a Structure. NASA

TT F-10,003, Feb. 1966.

117. Bishop, R.E.D.; and Gladwell, G.M.L.: An Investigation into the Theory

of Resonance Testing. Phil. Trans. Roy. Soc., London, ser. A, vol.

255, no. 1055, Jan. 17, 1963, pp. 241-280.

118. Pendered, J.W.: Theoretical Investigation into the Effects of Close

Natural Frequencies in Resonance Testing. J. Mech. Eng. Sci., vol.

7, no. 4, Dec. 1965, pp. 372-379.

119. Turner, L.J., Jr.: An Analytical Investigation of a Vector Technique

for Determining Normal Mode Amplitudes from Vibration Data. M.S.

Thesis, Virginia Polytech. Inst., May 1968.

120. Brann, R.P., Devney, A.J.; and Robinson, C.D.: Harmonic Excitation of

a Lightly Damped Multi-Degree System. Bull. Mech. Eng. Education, vol.

5, no. 2, 1966, pp. 95-111.

121. Rodden, W.P.; and Whittier, J.S.: Damping of Shaker-Excited Beams

Calculated Solely from Displacement-Amplitude Measurements. J.

L42

Acoust. Soc. Amer., vol. 34, no. 4, Apr. 1962, pp. 469-471.

122. Wambsganss, M.W., Jr.; Boers, B.L.; and Rosenberg, G.S.: Method for

Identifying and Evaluating Linear Damping Models in Beam Vibrations.

Shock & Vib. Bull., Bull. 36, Pt. 4, U.S. Dept. Defense, Jan. 1967,

pp. 65-74.

123. Stahle, C.V.; and Forlifer, W.R.: Ground Vibration Testing of Complex

Structures. Proc. AIA-AFOSR Flight Flutter Testing Sympos., May

1958.

124. Stahle, C.V.: A Phase Separation Technique for the Experimental

Determination of Normal Vibration Modes of Flight Vehicles. Shock

& Vib. Bull., Bull. 29, Pt. 4, U.S. Dept. Defense, 1961, pp. 30-42.

125. Stahle, C.V., Jr.: Phase Separation Technique for Ground Vibration Test-

ing. Aerospace Eng., vol. 21, no. 7, July 1962, pp. 56-57, 91-96.

126. Hutton, F.E.: The Application of the Component Analyzer in Determin-

ing Modal Patterns, Modal Frequencies, and Damping Factors of Lightly

Damped Structures. Shock & Vib. Bull., Bull. 33, Pt. 2, U.S. Dept.

Defense, Feb. 1964, pp. 264-272.

127. Gladwell, G.M.L.: A Refined Estimate for the Damping Coefficient.

J. Roy. Aeron. Soc., vol. 66, no. 614, Feb. 1962, pp. 124-125.

128. Keller, A.C.: Vector Component Techniques: A Modern Way to Measure

Modes. Sound &Vib., vol. 3, no. 3, Mar. 1969, pp. 18-26.

129. Smart, T.E.: Dynamic Phase Plotting. Shock & Vib. Bull., Bull. 37, Pt.

2, U.S. Dept. Defense, Jan. 1968, pp. 77-85.

143

130. Pallett, D.S.: System for the Complex Plane Representation of Mechan-

ical Vibration Response Parameters. Rept. TM 107.2811-06, Ord. Res.

Lab., Penn. State Univ., State College, Pa., Mar. 13, 1969.

131. Tendered, J.W.; and Bishop, R.E.D.; The Determination of Modal Shapes

in Resonance Testing. J. Mech. Eng. Sci., vol. 5, no. 4, Dec. 1965,

pp. 379-385.

132. Schoenster, J.A.; and Clary, R.R.: Experimental Investigation of the

Longitudinal Vibration of a Representative Launch Vehicle with Sim-

ulated Propellants. NASA TN D-4502, May 1968.

133. Clary, R.R.; and Turner, L.J., Jr.: Measured and Predicted Longitudi-

nal Vibrations of a Liquid Propellant Two-Stage Launch Vehicle. NASA

TN D-5943, Aug. 1970.

134. Bray, P.M.; and Egle, D.M.: An Experimental Investigation of the Vibra-

tion of Thin Cylindrical Snells with Discrete Longitudinal Stiffening.

Jour. Sound & Vib., vol. 12, no. 2, June 1970, pp. 152-164.

135. Schoenster, J.A : Measured and Calculated Vibration Properties of Ring-

Stiffened Honeycomb Cylinders. NASA TN D-6090, Jan. 1971.

136. Pendered, J.W.; and Bishop, R.E.D.: Extraction of Data for a Sub-System

from Resonance Test Results. J. Mech. Eng. Sci., vol. 5, no. 4, Dec.

1965, pp. 368-378.

137. Woodcock, D.L.: On the Interpretation of the Vector Plots of Forced

Vibrations of a Linear System with Viscous Damping. Aeron. Quart.,

144

vol. 14, no. 1, Feb. 1963, pp. 45-62.

138. Nissim, E.: On a Simplified Technique for the Determination of the

Dynamic Properties of a Linear System with Damping. J. Roy. Aeron.

Soc., vol. 71, no. 674, Feb. 1967, pp. 126-128.

139. de Vries, G.: Sondage des systemes vibrants par masses additionelles.

La Recherche Aeronautique, no. 30, Nov.-Dec. 1952, pp. 47-49.

140. Zener, C.: Mechanical Behavior of High Damping Metals. J. Appl.

Phys., vol. 18, no. 11, Nov. 1947, pp. 1022-1025.

141. Rogers, T.G.; and Pipkin, A.C.: Asymmetric Relaxation or Compliance

Matrices in Linear Viscoelasticity. Zeits. f. angew. Math. u.

Physik, vol. 14, 1963, pp. 334-343.

142. Busching, H.W.: Mechanical Behavior of Transversely Anisotropic

Materials. Proc. (First) Canadian Congr. Appl. Mech., Laval Univ.,

Quebec, Canada, May 22-26, 1967, vol. 1.

143. Alley, V.L., Jr.; and Faison, R.W.: Decelerator Fabric Constants

Required by the Generalized Form of Hooke's Law. AIAA Paper 70-1179,

presented at the AIAA 3rd. Aerodynamic Deceleration Systems Con-

ference, Wright-Patterson Air Force Base, Ohio, Sept. 14-16, 1970.

144. Bert, C.W.; and Guess, T.R.: Mechanical Behavior of Carbon-Carbon

Filamentary Composites. Composite Materials: Testing and Design

(Second Conference), Amer. Soc. Testing & Matls. Spec. Tech.

145

Publ. 497, 1972, pp. 89-106.

145. Todhunter, I.; and Pearson, K.: A History of the Theory of Elasticity

and of the Strength of Materials. Dover Publications, Inc., New

York, 1960.

146. Love, A.E.H.: A Treatise on the Mathematical Theory of Elasticity,

4th. Ed. Dover Publications, Inc., New York, 1944, chap. III.

147. Bert, C.W.; Mayberry, B.L.; and Ray, J.D.: Behavior of Fiber-Reinforced

Plastic Laminates Under Biaxial Loading. Composite Materials:

Testing and Design, Amer. Soc. Testing &Matls., Spec. Tech. Publ.

460, 1969, pp. 362-380.

148. Hadcock, R.N.: Boron-Epoxy Aircraft Structures. Handbook of Fiber-

glass and Advanced Plastics Composites, ed. by G. Lubin, Van

Nostrand Reinhold, 1969, pp. 628-660.

li>9. Chou, P.C;, Carleone, J., and Hsu, C.M.: Elastic Constants of Layered

Media. J. Composite Matls., vol. 6, no. 1, Jan. 1972, pp. 80-93.

146

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Figure 1. Composite containing undirectiona1 fibers.

THICK MIDDLE PLY WITHIDENTICAL OUTER PLIES

ODD NUMBER OFALTERNATING PLIES

Figure 2. Examples of symmetrical laminates.

151

LINES REPRESENTINGMAJOR MATERIAL-SYMMETRYAXES (FIBER DIRECTIONS)OF THE INDIVIDUAL PLIES

Figure 3. An example of a balanced laminate.

Figure 4. Plate coordinate system.

is:

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CONTACT SURFACE

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Figure 5. Lamination geometry, showing upper half of plate. '(Plane xyis the midplane of the plate).

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155

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THIN PLATE THEORY

TIMOSHENKO TYPE THEORY

JOURAWSKI SHEAR THEORY

SHEAR-FLEXIBLEPLATE THEORY

0.10 0.30 0.50 0.70 0.90SHEAR FACTOR K

Figure 13. Lowest Eigenvalue (A) for homogeneous, isotropicplate.

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THIN-PLATE THEORY

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Figure 14. Lowest e igenvalues (X) for three-ply symmet r i c a l l ylaminated p la te .

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Ref. 13 Calculated

Present Calculation O

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Figure 19. Nodal patterns of the first five mooes of compositematerial plates at angle of orientation 6 = 3C'fl

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Ref. 13 Measured

Present CalculationMODE

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1 0

PLATETHICK-NESS

Figure A-l. Shingle-laminated plate.

171

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172

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174

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175

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SOME DAMPING

MORE DAMPING

FREQUENCY

Figure B-4. Effect of damping on magnification factor.(Not drawn to scale).

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LARGE DAMPING

FREQUENCY.w

Figure B-5, Effect of damping on half-power-point frequencyseparation (Ofy-it)]) . (Not drawn to scale).

176

IMAGINARYCOMPONENT

(LOSSMODULUS)

REALCOMPONENT

(STORAGE MODULUS)

Figure B-6. Concept of complex modulus and loss angle.

RESPONSE

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TIME

Figure B-7. Exponential decay. (Not drawn to scale).

17;

FIBER MATRIX

LAYER "aLAYER "b"LAYER *Q*-LAYER "b"

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178

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