SPALLATION ANALYSIS WITH A CLOSED TRANS-SCALE FORMULATION OF DAMAGE EVOLUTION

A closed,trans-scale formulation of damage evolution based on the statistical mi-crodamage mechanics is summarized in this paper.The dynamic function of damage bridges themesoscopic and macroscopic evolution of damage.The spallation in an aluminium plate is studied withthis formulation.It is found that the damage evolution is governed by several dimensionless parameters,i.e.,imposed Deborah numbers De;and De,Mach number M and damage number S.In particular,the most critical mode of the macroscopic damage evolution,i.e.,the damage localization,is deter-mined by Deborah number De;.Deborah number De;reflects the coupling and competition betweenthe macroscopic loading and the microdamage growth.Therefore,our results reveal the multi-scalenature of spallation.In fact,the damage localization results from the nonlinearity of the microdamagegrowth.In addition,the dependence of the damage rate on imposed Deborah numbers De;and De,Mach number M and damage number S is discussed.