The influence of residual stress on the yielding of metal matrix composites

Abstract A systematic numerical study of the effect of residual stresses on the yielding behavior of composites comprised of elastic particles well bonded to a ductile matrix is carried out. The calculations are made within the framework of continuum plasticity theory using cell models. An investigation is made into the roles volume fraction, particle shape, and hardening play in this interaction. A slight transient softening of the composite in both tension and compression is found, but the limit stress of the composite is unaffected by the residual stress. Thus the limit stress-strain response is symmetric in tension and compression for strains greater than a few times the matrix yield strain. A qualitative connection is made between the transient reduction in stiffness and the extent to which there was prior plastic deformation in the matrix due to residual stresses.