ES 246 Project: Effective Properties of Planar Composites under Plastic Deformation

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ES 246 Project Effective Properties of Planar
Composites under Plastic Deformation
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Outline
1. Effective Properties of Composite Materials
2. Model Description3. Model Validation4.
Effect of Inclusion Shapes5. Isotropic/Kinematic
Hardening6. Conclusion and Future Work
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1. Effective Properties of Composite Materials
Objective of the Research
1. By introducing small amount of inclusion phase
to improved the bulk properties of the matrix.
(Evans A. Low-dielectric high-stiffness porous
silica)
2. To formulate equations for accurate prediction
of the effective properties of composite
materials.
Torquato S. et al Mean Field Theory for
Effective Modulus of Linear Elastic Composite
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2. Model Description -Composite Generation
Criteria for Inclusion Phase1. Random
coordination2. Random orientation3. No
overlapShape of Inclusion Phase1.
Triangular2. Square3. CircularVolume fraction
of Inclusion Phase 0.2Inclusion number 30
1cm
1cm
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2. Model Description -Materials Properties
Matrix Inclusion
E (GPa) 100 200
(GPa) 2 4
n (-) 0.5 0.5
Constitutive Law
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2. Model Description -Finite Element Mesh
Triangular Inclusion
Rectangular Inclusion
Element Type 4-Noded-Element Dominant Element
Size (Edge length) 0.1 mm Mesh
Sensitivity Refined-mesh model gives similar
results.
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3. Model Validation -Effective Modulus of the
Composite
(Based on Mean Field Theory for Linear Elastic
Material)
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3. Model Validation -Theoretical and Simulated
Youngs Modulus
Theoretical
Simulated
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3. Model Results -Effects of Inclusion Shapes
Effective Electric Conductivity with High
Conductivity Inclusions Triangular gt Square gt
Circle (Both Experiments and Theory)
Effective Tangent Modulus with Stiffer
Inclusions Triangular gt Square gt Circle Still
True?
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3. Model Results -Effects of Inclusion Shapes
Effective Tangent Modulus Triangular Square
Circle
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3. Model Results -Von Mises Stress Distribution
Max 9.629 GPa
Max 12.605 GPa
Max 8.827 GPa
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3. Model Results - Isotropic or Kinematic
Hardening (circular inclusion)
(Bilinear constitutive relations assumed for
matrix and inclusion)
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3. Model Results - Isotropic or Kinematic
Hardening (triangular inclusion)
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3. Model Results - Isotropic or Kinematic
Hardening (Effective Plastic Strain)
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Conclusion
1. We calculate the effective elastoplastic
properties of composite material with an stiffer
inclusion phase. The volume ratio of the
inclusion is 0.2.2. The shape of the inclusion
phase has no effect on the effective tangent
modulus of the material. 3. The triangular
inclusion phase gives the highest maximum Von
Mises stress in the matrix, and followed by the
rectangular inclusion phase. The circular
inclusion phase gives the most uniform stress
distribution. 4. The hardening type of the
composite is dominant by the matrix phase.
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4. Future Work -3D Modeling is Possible