Application of damage mechanics to the analysis of spall damage

A systematic method of spall damage analysis was developed on the basis of damage mechanics. By use of a scalar damage variable, the damage evolution equation of Lemaitre et al. and the viscoplastic constitutive equation of Perzyna modified for damaged materials were incorporated into the commercial finite difference program MANJUSRI-3 D for nonlinear dynamic analysis. The spall damage process, and stress wave propagation and temperature histories were analyzed for plate impact of OFHC copper disc targets. The computational results for the stress history and the particle velocity at the rear surface of the target plates were compared with the corresponding experimental results.