Creep of open-cell Voronoi foams

The power-law creep of open-cell Voronoi foams is calculated using finite element analysis. The results are used to determine the geometrical constants in the power-law creep model for an open-cell foam with a random microstructure. In some foams, individual struts may be missing, either through fracture, as is the case in some metallic foams, or through resorption, as is the case in osteoporotic trabecular bone. Analysis of the effect of random removal of struts within the foam on the creep rate indicates that it can have a dramatic effect: removal of only a few percent of the struts can increase the creep rate by one to two orders of magnitude.