experimental and numerical study on thermal aging and...

MSC.Software VPD Conference | July 17-19, 2006 | Huntington Beach, California

Experimental and Numerical Study on Experimental and Numerical Study on Thermal Aging Thermal Aging andand Mechanical Mechanical

Properties of Properties of Composite Army BridgeArmy Bridge

Ayman Mosallam, Ph.D., P.E.University of California at Irvine, CA

Larry Russell, PH.D.Army Research Office, Research Triangle Park, NC

Ramki Iyer, MCEArmy-TARDEC, Warren, MI

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Project Team Members

Alpha Star Corp.

University of California, Irvine

The Boeing Company

Project Team Members

Alpha Star Corp.

University of California, Irvine

The Boeing Company

Project SponsorProject SponsorU.S. Army's Tank-

automotive and Armaments COMmand [TACOM]

U.S. Army's Tank-automotive and Armaments

COMmand [TACOM]

U.S. Army Research Office

[ARO]

U.S. Army Research Office

[ARO]

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OUTLINEThis presentation summarizes the activities that have been conducted during the a research project focusing on thermal aging of the military composite bridges.

The project was Funded by US Army Research Office (ARO)

COMPOSITECOMPOSITEARMYARMY

BRIDGE [CAB]BRIDGE [CAB]

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Assault BridgingAssault Bridging

Wolverine BridgeWolverine Bridge

Armored Vehicle Launched Bridge

Armored Vehicle Launched Bridge

Improved Ribbon BridgeImproved Ribbon Bridge

Standard Ribbon BridgeStandard Ribbon Bridge

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BackgroundMilitary composite bridges offer many unique

advantages for the army including

lightweight weight (high strength-to-weight ratio),

superior corrosion resistance properties that are preferred in harsh environmental conditions.

The lightweight features of composite is an attractive and essential property fulfilling the goal of the US Army in producing lighter bridging components that require

less skill/craftsmanship to manufacture, less equipment and manpower to transport and repair

as well as being cost effective in the long run.

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Allowable or Negligible Damage

Interim Interim

Repairable Damage

TYPES OF DAMAGES

Major or Irreparable Damage

Temporary Temporary

Allowable or Negligible Damage

Interim Interim

Repairable Damage

TYPES OF DAMAGESTYPES OF DAMAGES

Major or Irrepairable Damage

Temporary Temporary

Permanent

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Diagnostic/Prognostic System (DPS) Concept

• The DPS system is designed such that the strain and other useful signals captured by the optical fiber sensors are transmitted remotely via a cellular phone line or other communication devices.

• Real-time field information are transmitted to different monitoring and control locations [e.g. bridging unit forward base or army headquarters.]

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Divert

Pass Slowly

Pass

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GENOA Full Hierarchical Modeling from Structural Scale to Micro-scale

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Collaborative Virtual testing (CVT) Website Collaborative Virtual testing (CVT) Website

Live Data Transmission and Analysis Live Data Transmission and Analysis -- 22

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What accuracy is availableWhat accuracy is available

What detail can be providedWhat detail can be provided

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Moving Loads Cyclic Laboratory (Real) & Computer-Simulated (Virtual) Tests of the Composite Army Bridge

Filed testing Filed testing --Progressive Fatigue Failure Analysis Progressive Fatigue Failure Analysis

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1 9 . 9 2 8 . 7 1 2 1 . 3 7 1 4 . 9 2 2 4 . 4 11 0 . 6 8

1 9 . 9 28 . 7 12 1 . 3 71 4 . 9 22 4 . 4 1

1 0 . 6 8

S u p p o r t B lo c k T r e a d w a y

D is t r i b u t o r B e a m

W h i f f le T r e e

A c t u a t o r

L o a d B lo c k s I n t e r n a l B u lk h e a d s

Max Moment Case [Loading Case 2]

Max Moment Case Max Moment Case [Loading Case 2][Loading Case 2]

Actuator Load and Displacements (ultimate Test)

What behaviors can be examinedWhat behaviors can be examined

Progressive Failure

Analysis of Composite

Bridge

Comparison between Full-Scale Experimental and GENOA Predicted Results for Load Case 2 (Max Moment)

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Thermal Aging Test MatrixThermal Aging Test MatrixStatic Tension

Static Compression

T/C Fatigue

Double V-Notch Shear

Group 1

Group 5Control

No-Load Thermal Aging Impact

No-Load Thermal Aging

Pre-Tension Thermal Aging

Pre-Compress Thermal Aging

UV Exposure

Static Tension

Static Compression

T/C Fatigue


Group 2

Group 3

Group 4

Group 6

Flexural Creep

Double Notch Shear Creep

Group 7

Creep

Static Tension

Static Compression

T/C Fatigue


Static Tension

Static Compression

T/C Fatigue

Double V-Notch ShearStatic Tension

Static Compression

T/C Fatigue


Static Tension

Static Compression

T/C Fatigue


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Results Results –– Control Case: Static PropertiesControl Case: Static Properties

Control – Mechanical Test and Simulation Prior to Thermal Cycling or UV Exposure

OCM Test Previous Seemann Test GENOA Simulation Property Modulus

(msi) Strength

(ksi) Modulus

(msi) Strength

(ksi) Modulus

(msi) Strength

(ksi) Tension 10.4 94.4 7.8 101.0 8.2 98.0 Compression 10.3 74.0 7.8 75.8 8.2 73 Shear 2.0 23.4 N/A N/A 3.3 26.4

GENOA simulation for this material was performed using the constituent properties derived from the Seemann test data.

The numerical predictions for the composite static properties inthe OCM tests are successful.

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Results Results –– Control Case: Evaluation of the Shear Test Using Control Case: Evaluation of the Shear Test Using GENOAGENOA

Failed around gripped areas

Shear stress distribution

Fractured areas

TestSimulation

Shear test was not successful due to the wrong failure location.

The reason for this failure is because the shear stress in the grip area is higher than the shear stress in the notched area.

The ASTM D 5379 shear test is not valid for this tri-axial material.

The Iosipescu shear test and simulation results are not reported in the subsequent sections due to the reasons above.

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Results Results –– Control Case: Fatigue Properties, and Effect of NoControl Case: Fatigue Properties, and Effect of No--Load Thermal CyclingLoad Thermal Cycling

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08Fatigue Cycle

Stre

ss L

evel

(Rat

io to

the

Tens

ile S

tren

gth)

Test-ControlTest - After No Load Thermal CyclingGENOA

T/C (R=-1) Fatigue(50 Cycles from (50 Cycles from ––27.4 F to 159.8 F)27.4 F to 159.8 F)

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Fatigue Cycle

Stre

ss L

evel

(Rat

io to

the

Tens

ile S

tren

gth)

Test-Control

GENOA-Control

Run Out. Test Stopped without Failure

T/C (R=-1) Fatigue

Matrix S-N degradation was derived based on this fatigue test.

Excellent match between simulation and test demonstrates the derived matrix S-N relation reflects the matrix fatigue behavior accurately.

Simulation indicates there was no damage that occurred during the thermal cycling process .

Test curve for the no load thermal cycling case is a little higher than the control, which must be caused by test scattering.

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Results Results –– Effect of PreEffect of Pre-- Tension and Compression Thermal Tension and Compression Thermal CyclingCycling

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Fatigue Cycle

Stre

ss L

evel

(Rat

io to

the

Tens

ile S

tren

gth)

Test-ControlTest - After Pre Tension Thermal CyclingGENOA

(30% of the UTS, 50 Cycles from (30% of the UTS, 50 Cycles from ––27.4 F to 159.8 27.4 F to 159.8 F) on Composite Fatigue PropertiesF) on Composite Fatigue Properties

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Fatigue CycleSt

ress

Lev

el (R

atio

to th

e Te

nsile

Str

engt

h)

Test-ControlTest - After Pre Compression Thermal CyclingGENOA

(30% of the UTC, 50 Cycles from (30% of the UTC, 50 Cycles from ––27.4 F to 159.8 27.4 F to 159.8 F) on Composite Fatigue PropertiesF) on Composite Fatigue Properties

Simulation indicates there was no damage that occurred during thermal cycling.

n sufficient reason to conclude that 50 pre-tension thermal cycles reduced the composite fatigue life.

Composite static tensile strength after 50 thermal cycles is a little higher than the control case, which may indicate the fatigue life variation is probably caused by material variation .

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Results Results –– Effect of NoEffect of No--Load Thermal Cycling (50 Cycles from Load Thermal Cycling (50 Cycles from ––27.4 F to 159.8 F): Impact Investigation27.4 F to 159.8 F): Impact Investigation

Diameter of the impactor head: 0.625 inches

Weight of the impactor: 10.8 pounds

Drop height of the impactor: 30.8 inches

Achieved impact energy (unit plate thickness): 1500 in-pound/in

1 inch

Test

Red area is the simulated damage area

Damage Areas in the Panel after Impact. The test picture is a C-Scan graph (2 ¼ MHZ. Ultrasonic Thru-Transmission C-Scan).

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Results Results –– Effect of NoEffect of No--Load Thermal Cycling, and Ultra VioletLoad Thermal Cycling, and Ultra Violet

(50 Cycles from (50 Cycles from ––27.4 F to 159.8 F) and 27.4 F to 159.8 F) and Impact on Composite Fatigue Properties

(313-Bulb Ultra Violet for 750 hours ) on Composite Fatigue PropertiesImpact on Composite Fatigue Properties

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Fatigue Cycle

Stre

ss L

evel

(Rat

io to

the

Tens

ile S

tren

gth)

Test-ControlTest - After ImpactGENOA-ControlGENOA - After Impact

0

0.2

0.4

0.6

0.8

1

1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08

Fatigue CycleSt

ress

Lev

el (R

atio

to th

e Te

nsile

Str

engt

h)

Test-ControlTest - After UVGENOA-ControlGENOA - After UV

The higher fatigue life of the composite after UV exposure should be caused by the material variability or due to test scattering.

GENOA simulation shows the 750-hour UV exposure did not influence the composite fatigue life

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Estimating the PostEstimating the Post--fire Strengthfire Strength1. Apply the thermal load as fire to the CAB deck2. The temperature distribution is used as inputs to progressive failure analyzer to evaluate the

damage due to fire. 3. Afterwards, the ultimate load is estimated as the post-fire residual strength with the damage

index imported to CAB progressive failure analysis model, and max shear loading case is applied.

Thermal load MSC.Nastran/Thermal Analysis

Temperature Distribution

GENOA/PFA Damage Pattern & Location

GENOA/PFAUltimate load (the Post-fire Residual

Strength)MaxShear Load

Stage 1:

Stage 2:

Stage 3:

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Internal damage distribution and damage pattern thirty Internal damage distribution and damage pattern thirty minutes after fire exposureminutes after fire exposure

Temperature Distribution was mapped to PFA modelMaterial properties (stiffness and Strength) were degraded with respect to temperature by Multi Factor Interaction ModelFailure modes and damage location, were assed by PFA

What behaviors can be examinedWhat behaviors can be examined

Damage distribution and pattern Damage distribution and pattern thirty minutesthirty minutes after fire exposureafter fire exposure

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Delamination in the Bulkhead, Crossover, and Beam Wall Surface

What behaviors can be examined What behaviors can be examined –– 1212

Resin damage in TBHB

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Thank you for your attention/Ayman

experimental and numerical study on thermal aging and...

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