Effects of strut geometry and pore fraction on creep properties of cellular materials

A set of analytical models based on engineering beam analysis is developed to predict creep behavior of cellular materials over a broad range of relative density. Model predictions, which take into account the presence of mass at strut nodes and consider different possible deformation mechanisms and foam architectures, are compared to experimental creep results for a replicated nickel-base foam and a reticulated aluminum foam. As porosity decreases, the controlling creep mechanism in the foams changes from strut bending, to strut shearing, and ultimately to strut compression.