Estimation of plateau stress of porous aluminum based on mean stress on maximum-porosity cross section

Abstract

Porous aluminum with high porosity is very lightweight and has high energy absorptivity. Plateau stress is an important mechanical property that is closely related to the energy absorptivity of porous aluminum. In this study, we attempt to estimate the plateau stress of porous aluminum by simply assuming that when the mean true compressive stress on a maximum-porosity cross section perpendicular to the direction of compressive loading reaches the critical value, a locally deformed layer appears and the nominal compressive stress becomes equal to the plateau stress. Through the comparison of compressive test results with the estimated results obtained according to this assumption, it was shown that the plateau stress can be evaluated approximately when the proof stress is used as the critical value. © 2013 The Japan Institute of Metals and Materials.