A PLASTICITY MODEL FOR THE SHOCK-WAVE BEHAVIOR OF PURE ALUMINAS

It is now established that the Hugoniot Elastic Limit and the beginnin g of the plastic wave of pure aluminas are controlled by the plasticit y of grains. It justified the development of a model of plasticity. Ou r analysis leads us to choose a strain-hardening law based on plastic strain. The parameters of this law are fitted on the experimental data obtained for the fully dense alumina Lucalox, and directly used for t he porous aluminas. The effect of initial porosity is taken empiricall y into account. Correlation between experiments and calculations are g ood for the tested aluminas. The limitations of the model for high ini tial porosities and high shock levels are discussed.