FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’S RATIO ...FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’S RATIO) MATERIAL FOR A BLASTRATIO) MATERIAL FOR A BLAST-PROTECTIVE DEFLECTOR Zheng-Dong

Unclassified: Dist. A Approved for public release

FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’S RATIO) MATERIAL FOR A BLAST-PROTECTIVERATIO) MATERIAL FOR A BLAST-PROTECTIVE

DEFLECTORZheng-Dong Ma, Gregory M. Hulbert, University of Michigan

Hongxin Bian Ce Sun MKP Structural Design Associates Inc

UNCLASSIFIED: Dist A. Approved for public release 1

Hongxin Bian, Ce Sun, MKP Structural Design Associates, Inc.Krishan Bishnoi, Farzad Rostam-Abadi, US Army TARDEC

August 19, 2010

Report Documentation Page Form ApprovedOMB No. 0704-0188

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering andmaintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information,including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, ArlingtonVA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if itdoes not display a currently valid OMB control number.

1. REPORT DATE 06 AUG 2010

2. REPORT TYPE Briefing Chart

3. DATES COVERED 07-01-2010 to 11-07-2010

4. TITLE AND SUBTITLE FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’SRATIO) MATERIAL FOR A BLAST-PROTECTIVE DEFLECTOR

5a. CONTRACT NUMBER W56HZV-09-C-0037

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S) Zheng-Dong Ma; Gregory Hulbert; Hongxin Bian; Krishan Bishnoi;Farzad Rostam-Abadi

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of Michigan,4260 Plymouth Road,Ann Arbor,Mi,48109

8. PERFORMING ORGANIZATION REPORT NUMBER ; #21087

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Army TARDEC, 6501 East Eleven Mile Rd, Warren, Mi, 48397-5000

10. SPONSOR/MONITOR’S ACRONYM(S) TARDEC

11. SPONSOR/MONITOR’S REPORT NUMBER(S) #21087

12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited

13. SUPPLEMENTARY NOTES For 2010 GROUND VEHICLE SYSTEMS ENGINEERING AND TECHNOLOGY SYMPOSIUM(GVSETS) AUGUST 17-19

14. ABSTRACT briefing charts

15. SUBJECT TERMS

16. SECURITY CLASSIFICATION OF: 17. LIMITATIONOF ABSTRACT

Public Release

18. NUMBEROF PAGES

32

19a. NAME OFRESPONSIBLE PERSON

a. REPORT unclassified

b. ABSTRACT unclassified

c. THIS PAGE unclassified

Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

Presentation Outline

θ2

θ2

θ2

θ2

θ1

θ1heθ1

θ1he

Application to blastFunctional and


NPRApplication to blast

protectionFunctional and

Functionally-graded NPR


θ2

θ2

θ2

θ2

θ1

θ1heθ1

θ1he






Negative Poisson’s Ratio (NPR) Material

• NPR materials first introduced in• NPR materials first introduced in 1987 (Lakes, Science)

• Unlike conventional materials, NPR materials may shrink whenmaterials may shrink when compressed along a perpendicular direction.

• Engineered NPR material concepta) NPR effect

ε

Original shape Deformed shape

• Engineered NPR material concept obtained from a topology optimization process (Larsen, 1997)

εy εx

• Extended to three-dimensional NPR design (patent pending)


b) NPR design from a topology optimization process (Larsen 1997)

Three-Dimensional NPR Material(MKP Patent Pending)( g)


(made of steel)

Design Variables

θ2

θ2

θ2

θ2 2mm X 5mmtendon

Unit Cell

θ

θ2

θ

θ2

θ1 = 60 degrees

θ1

θ1heθ1

θ1he

θ2 = 130 degrees

he = 22.2 mm

3mm X 5mm


stuffer

Effective Material Properties

6

7

(GPa)

0

θ2

heθ1

4

5

's Modulus

-40

-30

-20

-10

n's Ratio

30

801

2

3

ctive Young

80

-70

-60

-50

Poisson

13040 60 80 100 120 140 160

0

1

Effec

3060

90120

150

4070

100130160

-80


Effective Young’s Modulus Effective Poisson’s Ratio

Variations of Arrangement

θ

θ2

θ

θ2 Unit Cell

θ1

θ1

θ2

heθ1

θ1

θ2

he

PPR-1 PPR-2

Parallel Configuration Diagonal configuration PPR config ration


Parallel Configuration (NPR-p)

Diagonal configuration (NPR-d)

PPR configuration(PPR-1/PPR-2)

Stiffness Comparison of NPR & PPR Materials

NPR materials are much

400

500

600

MPa)

stiffer and stronger than PPR materialsWhen normal pressure i

NPR-diagonal

200

300

400

g's Modulus ( increases

– Stiffness of NPR material increases

– Stiffness of PPR material

NPR-parallel

PPR-2

0

100

200

Youn

decreasesNPR diagonal material– Is the strongest

PPR-1PPR 2

Young’s Modulus with respect to normal pressure

0 5 10 15 20

Vertical Pressure (MPa)NPR parallel material– Is the second strongest


g p pSame weight and same area density (area density of the NPR-diagonal is 2X)

Manufacturing Process forCoupons Development

Manufacturing process


Prove manufacturability and fabrication methodDevelop testing specimens

Virtual Blast Testing

6 kg TNTParameters:TNT: 6kg with offset 75cm

Material: Steel

Tensile: 2 0 mm x 2 0 mm

g

0.75 m

Top plate

140 mm

140 mm

Top plate

140 mm

140 mm

Tensile: 2.0 mm x 2.0 mm

Stuffer: 2.0 mm x 4.0 mm

Plate thickness: 3.0 mm

Theta 1: 60 deg

Tensile material

Stuffer material96.8

mm

Tensile material

Stuffer material96.8

mm

Theta 2: 130 deg

Cell unit periodicity in x: 4

Cell unit periodicity in y: 4

Cell unit periodicity in z: 4

Bottom plateBottom plate

Cell unit periodicity in z: 4

Damping: 0.1%

BCs: nodes on bottom plate no displacement in vertical direction


Simulation Result

Deformation and effective Von Mises stress


Deformation and effective Von Mises stress on the top plat (in Mbar)

Blast Force Mitigation

6 kg TNT

7

8

g

0.75 m

4

5

6

5 N)

5 N

)

2

3

4

force (e5

Forc

e (e

-1

0

1

0 200 400 600 800 1000 1200


time (us)Time (μs)

Unique Features of the NPR Material

Basic Features of the NPR (Negative Poisson’s Ratio) Material:

0.2

0.3

0.4

0.5

0.6

force in Z (e7 N)

NPR structure

RHA structure

4 ft 2 ft

8.3 inch

4 ft 2 ft

8.3 inch

4 ft 2 ft

8.3 inch

1 lb TNT

1 lb TNT1 lb TNT

4 ft 2 ft

11.5 inch

4 ft 2 ft

11.5 inch

ast Force (10

7 N)

Without NPR

With NPR

Material concentration Bulging effect

0

0.1

0 200 400 600 800 1000 1200

time (us)

total

Total Bla

Time (10‐6 Sec)

With NPR

Impact force mitigation

Functional and Functionally-Graded Design


Optimal Shape DesignAdaptive Shape Change


θ2

θ2

θ2

θ2

θ1

θ1heθ1

θ1he






Generalized Design Variables

• Various filling materialsOr no filling Tendon

Unit Cell • Metallic strip• Cable• Organic fiber

• Or no filling

θ2xθ2y g

• …

θ1x θ1y h

• Various geometry shapes


Stuffer• Various geometry shapes

and raw material selections

NPR by Design

PR(Y) =

1.80

PR(Y) =

‐2.5

PR(Y) =

0.7

PR(X) = ‐8.3

θ2x = 90oθ2x = ‐110o θ2x = 110o

PR(X) = ‐2.5PR(X) = 0.7


θ2y = ‐110oθ2y = ‐110o θ2y = 110o

Functionally-Graded NPR

Layer 7: E = 4.5e3MPa, ν = −0.79

Layer 6: E = 3.8e3MPa, ν = −0.50

Layer 5: E = 3.2e3MPa, ν = −0.31

Layer 4: E = 2.7e3MPa, ν = −0.18

Layer 3: E = 2 1e3MPa ν = 0 10

Layer 1: E = 1.3e3MPa, ν = 0

Layer 2: E = 1.7e3MPa, ν = −0.04

Layer 3: E = 2.1e3MPa, ν = −0.10

Layer 1: E 1.3e3MPa, ν 0

The integrated structure’s properties are: E = 2 8e3MPa ν = -0 24


The integrated structure s properties are: E 2.8e3MPa, ν 0.24

Simulation Result


The “Reactive” Deflector Concept

Based on the bulging effect of NPR material

Is enhanced by a functionally-graded NPR concept with varied stiffness along the lateral direction


g

Varied Stiffness Distribution


Adaptive Structure for Blast Protection

a) T1=150 μs b) T2=210 μs

c) T3=270 μs d) T4=330 μs


c) 3 0 μs d) 330 μs


θ2

θ2

θ2

θ2

θ1

θ1heθ1

θ1he






Objective

Develop an innovative structural-material conceptDevelop an innovative structural material concept for a novel deflector that can significantly improve crew protection under explosives with minimum

hi l i ht d C G h i htvehicle weight and C.G. height

– New structural-material configuration, which can react to the blast of explosives and improve protection bythe blast of explosives and improve protection by adaptively changing material configuration

– Maximize blast protectionMinimize vehicle weight– Minimize vehicle weight

– Minimize vehicle C.G. height– Can be functionally designed


Accomplishments

θ1

θ2

θ2

hθ1

θ2

θ2

hθ1heθ1he

Concept development PrototypingManufacturing process


Design optimization Mechanical & blast testsNew design capabilities

Drop Tower Tests

TST61: without NPRTST62: FG-NPR (1.0/1.2/

1 8 i h f )1.8 mm with foam)TST63: NPR (1.0 mm)

without foamTST64: NPR (1.0 mm) with

ffoam

Bas

erc

e to

the

B

Sample height after test

Pea

k Fo

r


A 50 kg mass from 12 feet heightSample #

Blast Tube Tests:BTR Composite vs. Honeycomb

Prof. Waas’ lab at U of M

Square honeycomb core panel (HC-1, HC-2): 5.5” X 5.5” X 1.6”. Weight: 506 g.g g

(made of steel)


Geometry of NPR: 5.5” X 5.5” X 3.5”,Weight: without foam: 398g, with foam:540g

( )

Comparison of NPR with Honeycomb

Boundary & loading conditions

Geometry of the square honeycomb core: 5.5” X 5.5” X 1.6”, Weight: 506g. NPR Honeycomb

Profiles of specimens after testing NPR t f hil

Helium 1,745 psi Helium 1,762 psi


NPR presents a convex surface, while square honeycomb presents a concave surfaceGeometry of NPR: 5.5” X 5.5” X 3.5”,

Weight: without foam: 398g, with foam:540g

Field Blast Test Plan

TNT Air Blast Parameter:TNT Air Blast Parameter:

Standard test: 6 kg =13.23 lb

0.5 m = 1.64 ft 1/3

Equivalent Air Blast Parameter:

Standard test: 1 lb and

0.69 ft = 21 cmScaled Distance= 0.69 ft/lb1/3 0.69 ft 21 cm


1 lb TNT 8” beneath the specimen of 12” x 12”

Before test

Convex surface


After test

Concluding Remarks

• Three unique features of the NPR material concept validated by• Three unique features of the NPR material concept-validated by both virtual prototyping and physical tests– Material concentration under the load – Bulging effect for blast wave deflection– Blast force mitigation

• NPR materials many perform much better than regular materials– Better stiffness and strength characteristics

B tt h i t t bl– Better shear resistance – more stable• Functionally-graded NPR design may provide

– Shape morphing and material redistribution, and hence better protection performanceprotection performance

– Less deflector height required for the same level of protection


Lightweight, Shape Adaptive Blast Deflector Conceptp

W-shape deflector

BTR deck/floor plate (Patent No.: US 7,563,497 B2)V-shape adaptive deflector


NPR adaptive deflector core(Patent Application No.: US 2010/0119792 A1)

Nanoclay‐reinforced composite front plate(Fiber-reinforced woven composite with nanoclay- reinforced matrix)

Documents

FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’S RATIO ...FUNCTIONALLY-GRADED NPR (NEGATIVE POISSON’S RATIO) MATERIAL FOR A BLASTRATIO) MATERIAL FOR A BLAST-PROTECTIVE DEFLECTOR Zheng-Dong