DUCTILE DAMAGE EVOLUTION ASSESSMENT IN HIGH PURITY COPPER AND STAINLESS STEEL SUBJECTED TO DIFFERENT SHOCK-LOADING PROFILES USING COHESIVE MODELING.

The calculated energy dissipation associated with the pull-back signal amplitude in plate impact experiment is usually larger than that obtained by accounting the contributions of the estimated plastic work at continuum scale and that due to ductile damage. As a possible explanation, it is proposed that the drop in the stress triaxiality, due to the formation of free surfaces as a result of the first appearance of the damage in form of voids, allows the matrix material to exhibit much larger plastic deformation. In order to verify this proposition, a numerical investigation based on the use of cohesive finite elements has been performed. The proposed numerical model has been used to predict the damage development and the rear pressure profile in a flyer plate impact test on 99.99% Cu and 316 L SS under flat top and triangular pressure wave profile. [ABSTRACT FROM AUTHOR]