IMPACT DAMAGE PATTERNS STUDIED BY A MODEL SIMULATION

A lattice model has been developed to explore impact damage patterns i n brittle materials. The damage evolution was modelled as a process in volving the change of strain-energy distribution by cracking. Using a cubic lattice system, a large strain energy was supplied to the system surface. Crack growth initiated by this local energy supply was follo wed by means of computer simulations. The damage patterns were compare d for systems which have different distributions of strain energy stor ed prior to the local energy supply. The simulations reveal a characte ristic difference in the damage pattern. Impact damage for a system wi th a spatially fluctuating distribution of strain energy is limited ar ound an impact point. Impact damage for a system with a relatively uni form distribution of strain energy penetrates deeply. The results of t he simulations are discussed in connection with the material evaluatio n and the material resistance.