The influence of void distribution on the yielding of an elastic-plastic porous solid

In a previous study, the authors proposed an anisotropic yield function for a porous metal. The present investigation extends the previous work by deriving a rate-type constitutive law based on the proposed yield function. A comparison is also made between yield loci derived from the yield function and those determined from an FE model. The FE calculations were performed for a flat plate, with a periodic array of cylindrical holes, under biaxial loading; and also for a porous solid with a periodic array of spherical voids under axial load and superimposed hydrostatic pressure. For the plate, the agreement between the yield function and numerical results was good, less so far the three-dimensional case. Good correspondence can be obtained by introducing a scalar multiplier in the pressure-dependent term in the yield function.