Experimental Investigation of the Dynamic Behavior of Aluminum Foams

The compressive behavior of two closed cell aluminum foams (Alporas and Cymat) were investigated under various strain rates from 10^-3 to 10² s^-1 using compressive tests conducted on MTS and Instron test machines. High speed camera videos show that localized deformation occurs in Alporas foam specimens uniformly, but not in Cymat foams. The stress-strain curves for Alporas foams are smooth and regular, while they oscillate dramatically for Cymat foams. Alporas foams exhibit strain rate sensitivity, i.e. with an increase in strain rate, the normalized plateau stress and energy absorption capacity increase. The plateau stress for Cymat foams was more sensitive than Alporas to strain rate, but the energy absorption less so, at least at a nominal relative density of 10%.