A Numerical Study of Plastic Strain Localization and Fracture in Al/SiC Metal Matrix Composite

Resumo

Plastic deformation and fracture of Al/SiC metal matrix composite have been numerically simulated in three mechanical tests (tension, compression, shear) with account for the microstructure and rheology of the composite components. A description is given of the formation mechanisms of stress concentration zones and local plastic deformation zones which make the stress-strain state inhomogeneous on the microscale. Distribution fields are obtained for the stress stiffness coefficient and the Lode-Nadai coefficient depending on the strain. Damage accumulation is simulated and damage distribution fields in the composite matrix are constructed with regard to the revealed stress-strain evolution laws. The strain dependences of the fraction of finite element nodes for which the fracture condition is fulfilled are determined. The dependences are used to estimate the damage accumulation rate in the composite matrix for each type of loading.