Abstract
Finite element calculations are performed on models of particulate metal-matrix composites to study the applicability of a quadratic yield function and an associated flow rule. The matrix, here taken to be Al, is described by a J 2 flow rule for an isotropic material and the reinforcing particles, either SiC or TiC, are taken to be elastic. Two different types of three-dimensional models of the composite are considered: (1) a simple cubic lattice of spherical particles and (2) random digital models that are approximately isotropic. Only in the second type of model can the existence of a flow rule be established. The validity of a flow rule in random models is associated with the absence of shear planes that extend throughout the solid without intercepting any particles. Such planes can be drawn in the simple cubic lattice for some shear deformations and particle volume fractions. Localized shear bands occurring on these planes results in a shear response essentially identical to that of the unreinforced matrix material, which precludes the determination of the shear response from the uniaxial deformation of the composite.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call