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Laminate Code Input

The composite laminate plate analysis code called LamCode_2c.exe will ask for various input as described

below. Note that all stored material data sets are described in English units (lbf, in). You must give all input in

(lbf, in) units. The program will allow the definition of additional material sets, and this is described later.

1. File name where output results are to be saved. By default, this file will be in the path/folder where the code

is located; however, the output file can be any place you want (be sure to include path name if appropriate).

2.

Plate dimension (L, W) in inches

3. Change in epoxy density (assumes 0.0405 lbf/in^3). You can change if desired.

4. The code has 9 material sets defined. You are asked if you want to define any additional material sets. If

you do, then you will be asked for the file name (a text file) which contains the material properties.

The materials are already defined (fiber/matrix):

1. S-Glass/epoxy

2. Woven-Glass/epoxy

3. Kevlar/epoxy

4.

Carbon/epoxy

5. Graphite/epoxy

6. Boron/epoxy

7. Boron/aluminum

8.

Silicon Carbide/aluminum

9.

Silicon Carbide/ceramic

5. Number of layers

6. Is layup symmetric, antisymmetric or none?

7. For each layer, input Material Set #, Thickness (inches), and Theta (+CCW from x-axis). Note that if the

layup is specified as symmetric or antisymmetric, then the program will ask for only the bottom portion of

the layup and will generate the rest. Example, if number of layers is 3, and symmetric, you will only be

asked to input 2 layers.

8. Do you want to consider hygrothermal effects (yes or no)?

9. If yes, then you will be asked for the temperature change (F) and moisture fraction (0 to 1).

10. Input the force and moment resultants: , , , , ,x y xy x y xN N N M M M y . Note that the units of force

resultants is lbf/in, and moment resultants is in-lbf/in. You must adhere to the sign convention for theseforces and moments as defined in the derivation of plate analysis (particularly moments, for example, xM

is a moment about the y-axis due to stress xx ).

Note: While the size of the plate is input, this information is only to calculate the weight of the plate. Since the

force and moment resultants are per unit length, the solution of stresses, strains, etc. is independent of the plate

size (i.e., the analysis is done for a unit width in the x and y directions).

WARNING ABOUT USING ONLY 1 LAYER (or a SMALL NUMBER of LAYERS): Using the code with

only 1 layer, or a very small number of layers, when there is significant bending can produce erroneous results.

With significant bending, the largest stresses (tensile or compressive) will be at the top of bottom of the plate

(with little stress at the middle of the plate). While the code calculates and outputs the stress and strain (in x-ycoordinates) at the top and bottom of each layer, and the stress and strain (in 1-2 material coordinates) at the

center of each layer, the failure criteria is only checked at the center of each layer. Consequently, if only one

layer is used and the there is significant bending which produces maximum stresses at the top or bottom of the

plate, there is a possibility that failure could occur at the extreme top or bottom of the plate, but this would not

be checked and possible failure would be overlooked by the code since the center of a plate in bending has very

low stress (and hence the failure criteria check would likely pass the test). But a visual check of actual

top/bottom stresses may actually indicate failure. One way to get around this problem is to break-up the plate

into several/many layers (each with less thickness) which then forces the code to do the failure criteria check at

locations closer to the top of bottom of the plate.

Optional material set requirements are described below.

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Input for Laminate Analysis Code Additional Material Set

The code allows for the definition of additional material sets. One example is shown on the following page.

Note that the input is fixed-field input and must following the format shown below. Note that there are seven

lines at the beginning of the file which are for information only (such as column spacing and other information);

these 7 lines may contain anything but cannot be omitted since the program will attempt to skip the first seven

lines of the input file. The blank lines are required also, and the last input line must be EOF. Note that all the

input begins on column 30, and the information in columns 1-29 is only identifying information. To create a

new input data set, take one of these existing files on the AERO 405 webpage (or the example file on the next

page) and change the information starting in column 30. Be sure that you store the file as a text file

Important:

The units used must be english units (lbf and inches). Likewise, the program input for the size and thickness of

the plate, the force and moment resultants, etc. should be in these units. Note that the Youngs moduli are given

in psi, but the ultimate stress values are given in ksi (you MUST follow this units convention). Ultimate strains

will be in/in.

The variables are defined on the following page. The directions 1 and 2 refer to the usual notation for laminate

directions: 1 = fiber direction, 2 = cross-fiber direction.

E1 Youngs modulus in fiber (1) direction, psi

E2 - Youngs modulus in cross-fiber (2) direction, psi

Nu12 Poissons ratio 12 , dimensionless

G12 Shear modulus in 1-2 plane, psi

Vf volume fraction (fiber to total volume), dimensionless

S1tu Ultimate tensile stress in fiber (1) direction, ksi

S2tu Ultimate tensile stress in cross-fiber (2) direction, ksi

S12u Ultimate shear stress in 1-2 plane, ksi

EP1u Ultimate strain in fiber (1) direction, in/in

EP2u Ultimate strain in cross-fiber (2) direction, in/in

S1cu Ultimate compressive stress in fiber (1) direction, ksi

S2cu - Ultimate compressive stress in cross-fiber (2) direction, ksi

alpha1 Coefficient of thermal expansion in fiber (1) direction, in/in/(F change)

alpha2 - Coefficient of thermal expansion in cross-fiber (2) direction, in/in/(F change)

beta1 Coefficient of moisture expansion in fiber (1) direction, in/in/(moisture fraction)

beta2 - Coefficient of moisture expansion in cross-fiber (2) direction, in/in/(moisture fraction)

rho (fiber) fiber density, lb/in^3rho (matrix) matrix density, lb/in^3

Note: If thermal change and/or moisture change effects (hygrothermal effects) are not beingconsidered as inputs (by inputting temperature change and/or moisture fraction), then the input of

alpha and beta coefficients is not requested by the code.

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1234567890123456789012345678901234567890123456789012345678901234567890123456789000000000011111111112222222222333333333344444444445555555555666666666677777777778

Not e: Type on col umn 30

Mater i al Name (Len. l e. 15) : : > Foam Core

E1 ( psi ) : : > 21. 8E3E2 ( psi ) : : > 21. 8E3

Nu12 : : > 0. 32G12 ( psi ) : : > 4. 785E3vf : : > 1. 00

S1t u ( ksi ) : : > 0. 392S2t u ( ksi ) : : > 0. 392S12u ( ksi ) : : > 0. 1885

EP1u ( 0. 01 f or 1%) : : > 0. 01EP2u : : > 0. 01

S1cu ( ksi ) : : > 0. 232

S2cu ( ksi ) : : > 0. 232

al pha1 ( i n/ i n/ F) : : > 0al pha2 : : > 0

beta1 : : > 0beta2 : : > 0

r ho ( f i ber ) ( l b/ i n 3) : : > 0. 0032r ho ( mat r i x) : : > 0

EOF

Fr om Mat web. com,ht t p: / / www. matweb. com/ search/ Speci f i cMater i al . asp?bassnum=PDI AB20DI AB Di vi nycel l HT 90 I nt erpenet r at i ng Pol ymer Net work Foam Core Mat eri al