Abstract
Nonlinear deformation of low-density porous marerials originates much mesoscopic and microscopic phenomena in compression process. Especially, the strain-rate dependency of its defomation has to be evaluated for precise analysis on the deformation. In this paper, some type of compression testing is conducted for inspecting the deformation behavior and over stress phenomena is observed in plateau region of compression process. And then the simple system of drop impact testing is developed to reserch the phenomena for the application of the materials to absorb shock of various machines. The formulation of viscoplastic constitutive equation will be studied by using the results of these experiments.
