Modeling and Modeling and Simulation for Simulation for Munitions Munitions Simulations* Simulations* Progress Report Progress Report PIs: Jacob Fish and Mark S. PIs: Jacob Fish and Mark S. Shephard Shephard Post-docs: Gal Davidi, Caglar Post-docs: Gal Davidi, Caglar Oskay Oskay Students: Zheng Yuan, Rong Fan Students: Zheng Yuan, Rong Fan *AFRL support leveraged by support from NSF, ONR and General Motors
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Adaptive Multiscale Modeling and Simulation for Munitions Simulations* Progress Report PIs: Jacob Fish and Mark S. Shephard Post-docs: Gal Davidi, Caglar.
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Adaptive Multiscale Adaptive Multiscale Modeling and Simulation Modeling and Simulation
for Munitions Simulations*for Munitions Simulations*
Progress ReportProgress ReportPIs: Jacob Fish and Mark S. ShephardPIs: Jacob Fish and Mark S. Shephard
Post-docs: Gal Davidi, Caglar OskayPost-docs: Gal Davidi, Caglar Oskay
Students: Zheng Yuan, Rong FanStudents: Zheng Yuan, Rong Fan
*AFRL support leveraged by support from NSF, ONR and General Motors
Roadmap of DevelopmentsRoadmap of DevelopmentsAssessment of commercial code Assessment of commercial code capabilitiescapabilities Mesh sensitivity studies (Gal Davidi) Mesh sensitivity studies (Gal Davidi) Validation studies (Rong Fan)Validation studies (Rong Fan)
Fragmentation capabilities for metalsFragmentation capabilities for metals Homogenization based approach (Gal Davidi)Homogenization based approach (Gal Davidi) Integration of homogenization in ABAQUS Integration of homogenization in ABAQUS
(Zhen Yuan) (Zhen Yuan) PUM based (Zhen Yuan and Rong Fan) PUM based (Zhen Yuan and Rong Fan)
Roadmap of Developments (cont)Roadmap of Developments (cont)Fragmentation capabilities for compositesFragmentation capabilities for composites Reduced order methodology (Oskay) Reduced order methodology (Oskay) Validation studies (Oskay)Validation studies (Oskay) Integration in ABAQUSIntegration in ABAQUS Multiscale Enrichment based PUM Multiscale Enrichment based PUM
ApplicationsApplications
Fragmentation in MetalsFragmentation in MetalsExperimental setupExperimental setup
Impactor in Sabot
Target Assembly
DH36 Steel Plate
The experimental parameters considered:• Steel target plate: DH36 steel; 3/16 inch thick; 6 inch diameter; • Impact velocity: In the range between 920 ft/sec. • Backing material: Polyurea: 0.215 inch• Impactor: non-deformable
Experiment vs ABAQUS simulationExperiment vs ABAQUS simulation (without backing) (without backing)
Mises stress (without backing)
Equivalent plastic strain (without backing)
Experiment vs SimulationExperiment vs SimulationDH36DH36
Drawbacks of commercial softwareDrawbacks of commercial software
Global (structure) EnrichmentGlobal (structure) Enrichment Enrich the kinematics of the global mesh with Enrich the kinematics of the global mesh with
failure characteristic (delamination, shear failure characteristic (delamination, shear banding, fragmentation) characteristic banding, fragmentation) characteristic computed on the local patchcomputed on the local patch
For computational efficiencyFor computational efficiency
Local (material) EnrichmentLocal (material) Enrichment Embed discontinuities (strong or weak) into Embed discontinuities (strong or weak) into
material (micromechanical) modelmaterial (micromechanical) modelFor regularization of failure modelsFor regularization of failure models
BetterBetter
Global Enrichment (MEPU)Global Enrichment (MEPU)
iN db b
Cell problems on
ijc
Q
Failure deformation mode-shapes
delamination
fracture
Global deformation modes
( )CoarseScale Enrichment
i i iA Au N d N ab b a ac= +G555555HG55H
x( )CoarseScale Enrichment
i i iA Au N d N ab b a ac= +G555555HG55H
x
Rigid body+Failure modes
ˆ ( )i iA Au N aa ac=GH
x
Rigid body+Failure modes
ˆ ( )i iA Au N aa ac=GH
x(Superposition) (Domain decomposition)
0
50
100
150
200
250
300
0 0.0001 0.0002 0.0003 0.0004
Time (s)
Velo
city
of
Impact
or
(m/s
)
Global Enrichment (metals)Global Enrichment (metals)3D simulations3D simulations
DH36 & ERC (3D-21 layers)
MEPU
DH36 & ERC (Shell)
Local Enrichment (metals)Local Enrichment (metals)(in progress)(in progress)
Calculate discontinuity direction at each Gauss point Calculate discontinuity direction at each Gauss point
Align the RVE local coordinate system with one of the Align the RVE local coordinate system with one of the axis normal to the localization planeaxis normal to the localization planeDevelop a 3-point RVE model as follows:Develop a 3-point RVE model as follows:
det 0T n Dn
1
2
3
4
6
78
5
Shell
n
RVEDiscontinuity plane
Gauss point
Constrained RGB
Constrained
periodicity
master
Impact Fragmentation of compositesImpact Fragmentation of composites PhenomenologicalPhenomenological