Finite element analysis of porous materials fracture toughness

Stress/strain fields of a crack tip in a porous material were investigated by the finite element method (FEM) using the elastic-plastic ABAQUS codes. The three-dimensional models simulated the spherical pores regularly distributing in front of a blunted crack tip. The analysis indicates that the maximum tensile stress and strain do not necessarily locate between the crack and the nearest pore. The location and magnitude of stress depend on the geometrical distribution of pores in the crack plane. The present work illustrates that the rationale of using K-IC to characterize the fracture resistance of engineering porous materials, such as sintered steel, can be explained by the critical stress model of fracture toughness.