Virtual Materials Testing Karel Matous College of Engineering - - PowerPoint PPT Presentation
Virtual Materials Testing Karel Matous College of Engineering - - PowerPoint PPT Presentation
Virtual Materials Testing Karel Matous College of Engineering Collegiate Associate Professor of Computational Mechanics Director of Center for Shock-Wave Processing of Advanced Reactive Materials Shock W ave - processing of Advanced Reactive
Department of Aerospace and Mechanical Engineering
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High Energy Ball Milling (HEBM)
Shock
C-SWARM Verification Prediction Validation/UQ Discovery
Truly multiscale in space, time, and constitutive equations Chemo-thermo-mechanical behavior Solid-solid state transformations
Shock W ave-processing of Advanced Reactive Materials
- Demonstration Ni/Al and Discovery c-BN systems
Department of Aerospace and Mechanical Engineering
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Mesoscale Microscale Nanoscale Macroscale
▪ Targeted Characteristics:
– Layer Thickness – Layer Tortuosity – Reactant Surface Area Contact
▪ Targeted Characteristics:
– Crystal Size – Crystal Shape – Crystal Orientation
▪ Targeted Characteristics:
– Porosity – Pellet Size and Shape
Ni/Al demonstration system Shock W ave-processing of Advanced Reactive Materials
▪ Targeted Characteristics:
– Particle Size – Particle Shape
Department of Aerospace and Mechanical Engineering
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Real material Surrogate medium macroscale microscale/mesoscale multiscale analysis statistical equivalence Model reduction
Macro-scale Meso-scale shock zone transition zone inert zone Micro-scale O(0.1 m) O(0.1 mm) O(0.1 μm) Macro-continuum Micro-continuum
Hierarchical multiscale modeling concept Microstructure-Statistics- Property-Relations Ensemble averaging Image-based (Data-Driven) Modeling
Department of Aerospace and Mechanical Engineering
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Real material Surrogate medium macroscale microscale/mesoscale multiscale analysis statistical equivalence Model reduction
Hierarchical multiscale modeling concept Microstructure-Statistics- Property-Relations Ensemble averaging
Macro-scale Micro-scale O(0.1 m) O(0.1 μm) Macro-continuum Micro-continuum O(0.1 mm) Meso-scale
Image-based (Data-Driven) Modeling
50 100 150 200 0.1 0.2 0.3 0.4 0.5 radius (µm) Srs Smm Sm4 Sm5 Sm6 S55
10 20 30 40 50 60 70 80 0.05 0.1 0.15 0.2 0.25 diameter (µm) volume fraction voxel pack cell
Department of Aerospace and Mechanical Engineering
pack cell
100μm
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scan - 19123 particles cell - 1082 particles scan - 1445x1288x798 cell - 400x400x400
µm µm
100μm
2048 CPUs cp = 53.91%
C
cp = 55.27%
T
cp = 54.20%
S
9- bins
Parallel Genetic Algorithm
N=500,000
Glass beads
Image-based (Data-Driven) Modeling
Department of Aerospace and Mechanical Engineering
Rice & Mustard - cp=0.667
µm
Resolution 69.4
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1.006 1.5777 2.1494 2.7211 3.2928 0.0201 0.1662 0.3124 0.4585 0.6046 5 10 15 20 25 30 d ε pdf 5 10 15 20 25 30
e D (mm)
Polydisperse Systems
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Ni-Al HEBM compact (blue=Ni)
raw data, processed data
Resolution ~5 nm
FIB/SEM (ND) Nano-tomography (Argonne) FIB/SEM - 5 nm Nano-tomography - 11.8 nm
Image-based (Data-Driven) Modeling
Department of Aerospace and Mechanical Engineering
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1µm
Nickel crystals mean 61.40 nm, variance: 6.36 nm2 Aluminum crystals mean 45.68 nm, variance: 0.66 nm2
Image-based (Data-Driven) Modeling
25 15 5 Count [1010] 660 3300 Thickness [nm] 2000 2 1
Effective Stress
Department of Aerospace and Mechanical Engineering
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Impact Simulations in Heterogeneous Materials
Ne = 6,690,165 Dofs = 3,431,023
fixed 1.0 mm 1.0 mm 1.0 mm v = 100 m/s periodic
- Aluminum powder
- Voce-Kocks hardening
80 ellipsoids 60% volume fraction
||σ||
10+3 10+1 100 [MPa] 10-3 Hardening 315 240 210 [MPa] 280
Δt = 0.1 ns
- LANL Mustang, 4800 cores
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Third-order statistics
- LANL Mustang, 7200 cores
HS bound TPA-WR spheres TPA-WR icosahedra TPA-WR dodecahedra TPA-WR octahedra TPA-WR hexahedra TPA-WR tetrahedra ke/km cp 1 0.2 0.4 0.6 4 7 10 13 16 19 icosahedra
- ctahedra
tetrahedra d d 2d 2d 3d 4d r1 r2 d 2d 3d 4d r2 d 2d 3d 4d r2 3d 4d q = 0°
- Morphology is important
Image-based (Data-Driven) Modeling
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Department of Aerospace and Mechanical Engineering
Heterogeneous Layers
- S. Xu, D. Dillard and J. Dillard
Welds From Internet
Department of Aerospace and Mechanical Engineering
- Cohesive modeling
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t ⟦u⟧ P P
traction-separation law
- Cohesive law based on lower scale physics
?
t ⟦u⟧ t ⟦u⟧ t ⟦u⟧
lRUC
Multiscale Modeling of Heterogeneous Layers
0t
q0u y
Department of Aerospace and Mechanical Engineering
- Critical assumption: lc ≪ ℴ(L)
0ϕ(X) = X + 0u(X)
∈ Ω±
0F = 1 + ⇥X 0u(X)
Ω±
Adherends
Multiscale Cohesive Model
Micro Interface
1ϕ(X, Y ) = 0F (X)Y + 1u(Y )
∈ Θ0 F =0F + ⇤Y
1u(Y )
=1 + 1 lc 0u(X) ⇥ 0N + ⇤Y
1u(Y )
⇥ Θ0
Macro Interface: Average Deformation Gradient
0ϕ(X) ⇥ =0ϕ+ − 0ϕ− = 0u(X) ⇥
- n Γ0
0F = 1 + 1
lc 0u(X) ⇥ ⊗ 0N
- n Γ0
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Matous et al., 2008 Mosby and Matous, 2014, 2015
̌
̌
⇥X · 0P + f = 0 Ω±
0P = ∂0W
∂0F Ω± ⇥Y · 1P = 0 Θ0
1P = ∂1W
∂F Θ0 F = 1 + 1 lc 0u(X) ⇥ 0N + ⇥Y
1u(Y )
Department of Aerospace and Mechanical Engineering
Strong and W eak Forms
Macroscale Strong Form Microscale Strong Form
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0P · N = tp
- n ∂Ωt
0u = 0u p
- n ∂Ωu
t+ + t− = 0
- n Γ0
Boundary Conditions Hill-Mandel Lemma
- Microscale weak form
- Yields closure on 0t
- Restrictions on BC
Macroscale Weak Form
0R =
- Ω±
0P : ⇥X(δ0u) dV
- Ω±
f · δ0u dV
- ∂Ωt
tp · δ0u dA +
- Γ0
0t ·
- δ0u
⇥ dA = 0
inf
0u⇥ 0W(
0u ⇥ ) = inf
0F inf 1u
lc |Θ0| ⇤
Θ0 1W
0F ( 0u ⇥ ) + Y
1u
⇥ dV
Department of Aerospace and Mechanical Engineering
Hill-Mandel Lemma
No assumption on form of 0t
0t = 0N ·
1 |Θ0|
- Θ0
1P dV
At microscale equilibrium
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Microscale Boundary Condition Admissibility
1u = 0
- n ∂Θ
1u+ =1 u− || ¯
t+ = −¯ t−
- n ∂Θ
¯ t = 0
- n ∂Θ
1 |Θ0|
- Θ0
Y
1u dV =
1 |Θ0|
- ∂Θ0
1u · N Θ dA = 0
1P = ∂1W
∂F
- F =0F +Y 1u
0t = ∂0W
∂ 0u⇥
1R = lc
|Θ0| ⇤
Θ0 1P : ⇥Y (δ1u) dV = 0
0u⇥R =
- 0N ·
1 |Θ0| ⇤
Θ0 1P dV 0t
⇥ · ⇤ δ(0u) ⌅ = 0
1W(F , ω) = (1 − ω)1W(F )
Department of Aerospace and Mechanical Engineering
Constitutive Response of Adhesive Layer
- Isotropic damage law
- Damage surface
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g(¯ Y , χt) = G( ¯ Y ) − χt ≤ 0 G( ¯ Y ) = 1 − exp ⇤ − ¯ Y − Yin p1Yin ⇥p2⌅ , H = ∂G( ¯ Y ) ∂ ¯ Y
- Irreversible dissipative evolution equations
- Different constitutive laws can be used
˙ ω = ˙ κH → ˙ ω = µ
- φ(g)
⇥ ˙ χt = ˙ κH → ˙ χt = µ
- φ(g)
⇥ ⇧ ⌅⇤ ⌃
viscous regularization
1/µ ≈ 𝜐 [s] Epoxy 𝜐-ℴ(10-6-10-2)
Department of Aerospace and Mechanical Engineering
- Digital Cell - 1000x1000x200 𝜈m3
Np = 4774
- 10 % volume fraction
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- 20 micron particles
1/2 lRUC lRUC 2 lRUC 1/2 lRUC - 70x70x200 𝜈m3 lRUC - 140x140x200 𝜈m3 2 lRUC - 280x280x200 𝜈m3 1/2 lRUC - Np = 23 lRUC - Np = 93 2 lRUC - Np = 374 Srs r [𝜈m]
50 100 150 0.2 0.4 0.6 0.8 1 Spp Spm Smp Smm 1/2 lRUC 1 lRUC 2 lRUC
lc = 200 𝜈m
1/2 lRUC
Image-Based Modeling, Heterogeneous Layers
JusK = p Jus1K2 + Jus2K2
Department of Aerospace and Mechanical Engineering
- Mixed mode loading ⟦un⟧=⟦us1⟧=⟦us2⟧=1/√2⟦us⟧
Representative Unit Cell Study
- Ne≃12,317,628
- Nn≃2,103,957
- Dofs≃6,280,495
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lRUC 2 lRUC •Ne≃48,537,975
- Nn≃8,294,617
- Dofs≃24,758,080
- Mean element size 1.5 𝜈m
- ˙
0u/lc
- = 1.00 [s−1]
- ˙
0u/lc
- = 0.01 [s−1]
- ˙
0u/lc
- = 0.10 [s−1]
0tn [MPa]
0un
- [µm]
5 10 15 18 36 54 72
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1/2 lRUC
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2 lRUC
RUC Study
ω lRUC
lcell ≈ 2 lstat lcell ≈ lstat lcell ≈ 1/2 lstat
0tn [MPa]
0un
- [µm]
1 2 3 4 5 6 9 18 27
Shear Normal
0tn [MPa]
lcell [µm]
50 100 150 200 250 300 8 9 10 23 24 25
Department of Aerospace and Mechanical Engineering
Multiscale Cohesive Model - Mixed Mode Loading
- Isocontours of ω ≥ 0.999
- 512 CPUs
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0.0 0.2 0.4 0.6 0.8
30.0 15.0 0.00
||𝝉||
- 2 lRUC - Np = 374
[MPa]
- 10 % volume fraction
- 20 micron particles
ω
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Particle Diameter Effect
- 10 % volume fraction
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5 𝜈m
- Smaller particles - higher strength
- Non-monotonic fracture toughness
20 𝜈m 10 𝜈m
d = 20 µm d = 10 µm d = 5 µm
0tn [MPa]
0un
- [µm]
2 4 6 9 18 27
Effect of constraint on Gn versus Gs
- H. Parvatareddy and D. Dillard, IJF 1999.
ω
Department of Aerospace and Mechanical Engineering
Particle Diameter Effect
- 10 % volume fraction
21
5 𝜈m
- Smaller particles - higher strength
- Non-monotonic fracture toughness
20 𝜈m 10 𝜈m
Shear Normal
Gs [MPa·µm] Gn [MPa·µm] d [µm]
5 10 15 20 25 30 35 40 45 50 55 55 60 65 70 75 80
Effect of constraint on Gn versus Gs
- H. Parvatareddy and D. Dillard, IJF 1999.
Department of Aerospace and Mechanical Engineering
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X2 X1 X3
t = 10 µs
High-Performance Computing
- Highly scalable finite strains
PGFem3D solver
- Multiscale FE2 capability
- Quasi-steady or transient analysis
- Complex constitutive Eq.
Ne = 123,168,768 Nn = 28,366,848 10 Nonlinear time steps 4 Linear iterations ∆t = 1 µs v = 1 m/s
1R = lc
|Θ0| ⇤
Θ0 1P : ⇥Y (δ1u) dV = 0
0u⇥R =
- 0N ·
1 |Θ0| ⇤
Θ0 1P dV 0t
⇥ · ⇤ δ(0u) ⌅ = 0
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Hierarchically Parallel Multiscale Solver
i = i+1 Initialize Send requests to microscale Check convergence No Yes Build macroscale Assemble from micro Done
Downscaling Upscaling Key Microscale Server
No Yes Check convergence j = j+1 Build Receive request from macroscale Send result to mactoscale
0R =
- Ω±
0P : ⇥X(δ0u) dV
- Ω±
f · δ0u dV
- ∂Ωt
tp · δ0u dA +
- Γ0
0t ·
- δ0u
⇥ dA = 0
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Macro-scale
- No-slip on top/bottom
- h= 20 mm, d = 20 mm
E = 205 GPa, ν = 0.25 320K elements in Macro Micro-scale
- 210 x 210 x 210 µm3
- 98 voids, 30 µm diameter
E = 3 GPa, ν = 0.29 10.2M elements in cell
- Nonlinear hyperelastic constitutive model
5296 RUCs
Generalized Computational Theory of Homogenization
Department of Aerospace and Mechanical Engineering
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9.43B Node, 53.75B Elements, 28.08B DOF
0.0 200 400 600 0.0 208 416 625
1 2
1 2
e
0.00 0.30 0.60 0.15 0.45
Multi-scale Simulations, PGFem3D - GCTH
he(min)=191 nm 5296 RUCs
σeq [MPa] ||0t|| [MPa]
- Full system on LLNL Vulcan — 393,216 cores, 786,432 threads
Department of Aerospace and Mechanical Engineering
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micro macro micro micro MPI_COMM_WORLD mm_inter micro_all
migrate Load-balancing for microscale simulations
- Time-based metrics for adaptation, load-
balancing heuristics
- Non-blocking data migration among
servers/computing nodes
- Overlay computations with data migration
Ideal 512 RUC 1k = 1024
Speedup
- No. of cores (servers)
4k (8) 8k (16) 16k (32) 32k (64) 64k (128) 128k (256) 256k (512) 1 2 4 8 16 32 64
RUC (512 cores) 1.46M Elements 262K Nodes 773K DOF
- LLNL Vulcan
- 262,114 cores
Multi-scale Simulations, PGFem3D - GCTH
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F i x e d
u
2 mm 40 mm 10 mm 5 mm
Macroscale
- Mode I loading
E = 15 GPa, ν = 0.25 10K elements 322 cohesive elements Microscale
- 250 x 250 x 125 µm3
- 40 voids, 40 µm diameter
E = 5 GPa, ν = 0.34 249K elements in RUC
322 RUCs
- 80M Elements, 42.5M DOFs
Multi-scale Simulations, PGFem3D - GCTH
Department of Aerospace and Mechanical Engineering
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Fully Coupled Multi-scale DCB Failure: Mode-I
||0t|| [MPa]
1
σeq [MPa]
2
- Numerically resolve O(105) scales (1 cm to 100 nm)
1 2 25 50 75 100 15 30 45 60
ω
0.0 1.0
5 10 15 20 25 0.5 1 1.5 2
Opening Disp. [µ m] Force [kN]
Opening Displacement [µm] Force [kN]
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Nonlinear Manifold-based Reduced Order Model
Digital Database
q
1 N
{ }
Isomap — Generalizes the Multidimensional Scaling Reproducing kernel map for reconstruction map Neural Network for input to reduce space map
Input parameters Manifold RUC simulations
Reduced space
- Homogenization and Localization capabilities
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0U = 0λ1(0e1 ⊗ 0e1) + 0λ2(0e2 ⊗ 0e2) + 0λ3(0e3 ⊗ 0e3),
Generating parameters — 6 HEALPix grid
Loading Case Description
- No. Simulations
Mode 1
0λ1 ≥ 0, 0λ2 ≥ 0, 0λ3 ≥ 0
4032 Mode 2
0λ1 ≤ 0, 0λ2 ≥ 0, 0λ3 ≥ 0
4032 Mode 3
0λ1 ≤ 0, 0λ2 ≤ 0, 0λ3 ≥ 0
4032 Mode 4
0λ1 ≤ 0, 0λ2 ≤ 0, 0λ3 ≤ 0
4032
Loading Modes
Ne = 486,051, DOFs = 250,035
cp = 0.4 95 particles
F = 0F (X) + rY 1u(Y )
Nonlinear Manifold-based Reduced Order Model Deformation gradient
- D = 9 × Ne = 4,374,459
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31 Mode − 4 Mode − 3 Mode − 2 Mode − 1 Residual Variance Dimension
1 2 3 4 5 6 7 8 9 10 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
- Reduced dimension
Pair-wise distance ξi and ξj Neighborhood graph G on M Geodesic distances Geodesic minimal spanning tree ➝ d - reduced dimension Low dimensional embedding, A ➝ ζi - reduced vectors Inverse map, f†N, link ζi and ξi Neural Network, link ηi and ζi
Digital Database
q
1 N
{ }
Nonlinear Manifold-based Reduced Order Model
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MNROM — V erification
ROM FEM Frequency [%] kF kF
1.42 1.67 1.92 2.17 2.42 2 4 6 8 10 12 14
403 leave-one-out cases for each Mode
Mode − 4 Mode − 3 Mode − 2 Mode − 1
Frequency [%]
0Em [%]
0.25 0.5 0.75 1 1.28 10 20 30 40 50 60
Er = kF ROM
r
F FEM
r
kF kF FEM
r
kF ⇥ 100 [%],
0Er =
1 Θ0 R
Θr ErdΘ
k0F rkF ,
- Averaged error in matrix
- Local distribution of F
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MNROM — Localization Characteristics
- Query point
Almansi strain
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MNROM — Homogenization Characteristics
FEM ROM k ˆ Ck
0WC( ˆ
C) [MPa] 1.735 1.745 1.755 1.765 1.775 0.2 0.4 0.6 0.8 1 1.2 1.4
FEM ROM J
0WJ(J) [MPa]
0.78 0.88 0.98 1.08 1.18 1.28 1 2 3 4
inf
0u
0W(0u) = inf
0u inf 1u
1 |Θ0| Z
Θ0 1W(0F + r
Y
1u) dΘ.
Source κ [MPa] µ10 [MPa] µ01 [MPa] MNROM 105 13.45 13.45 FEM 94 12.40 12.40
- Median error 10%
- 400 Query points
Effective properties Homogenized potentials
Department of Aerospace and Mechanical Engineering
Real material Surrogate medium macroscale microscale/mesoscale multiscale analysis statistical equivalence Testing inside scanner Numerical analysis Macroscale Validation Model reduction Mesoscale Validation
3µm resolution
Modeling with Co-Designed Experiments
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Microtomography In Situ Testing
Displacment [mm] Force [N] 1 2 3 4 5 6 10 20 30 40 50 60 70 80 Average Loading Average Unloading
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Material System
200-300 µm glass beads Silicone rubber matrix Pure rubber - Calibration Np,cylinder ≈ 35,000 Np,VO = 11,686 cp = 0.505
5 mm
20 40 60 0.01 0.02 0.03 0.04 0.05 0.06 0.07 radius (µm) pdf
rmax 106 µm ravg ~25 µm
2 4 6 50 100 150 200 250 300 Displacment [mm] Force [N] Loading/Unloading 1 Loading/Unloading 2 Relaxation Point Image
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Microtomography In Situ Testing
voids after debonding
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Nv = 17,008
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“Virtual” FE2 Micro-computer Tomography
3µm resolution
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1x1x1 cm3 = ℴ(1012) voxels detectability ~ 1 micron 1x1x1 mm3 = ℴ(109) elem. mean element size ~ 1 micron
- 1000 RUCs
- Trillion number of elements
- Billion number of equations
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Conclusions
- Thanks to Colleagues, Research Staff, Students