Hierarchical Finite-Element Modeling of SiCp/Al2124-T4 Composites with Dislocation Plasticity and Size-Dependent Failure

전위 소성과 크기 종속 파손을 고려한 SiCp/Al2124-T4 복합재의 계층적 유한요소 모델링

  • Received : 2011.10.31
  • Accepted : 2011.12.02
  • Published : 2012.02.01


The strength of particle-reinforced metal matrix composites is, in general, known to be increased by the geometrically necessary dislocations punched around a particle that form during cooling after consolidation because of coefficient of thermal expansion (CTE) mismatch between the particle and the matrix. An additional strength increase may also be observed, since another type of geometrically necessary dislocation can be formed during extensive deformation as a result of the strain gradient plasticity due to the elastic-plastic mismatch between the particle and the matrix. In this paper, the magnitudes of these two types of dislocations are calculated based on the dislocation plasticity. The dislocations are then converted to the respective strengths and allocated hierarchically to the matrix around the particle in the axisymmetric finite-element unit cell model. The proposed method is shown to be very effective by performing finite-element strength analysis of $SiC_p$/Al2124-T4 composites that included ductile failure in the matrix and particlematrix decohesion. The predicted results for different particle sizes and volume fractions show that the length scale effect of the particle size obviously affects the strength and failure behavior of the particle-reinforced metal matrix composites.


$SiC_p$/Al2124 Composites;Strain Gradient Plasticity;Finite Element Modeling;Dislocation Punching;Particle-Size-Dependent Failure


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