The application of the damage & fracture material model to crashworthiness evaluations for Aluminum cars

In an evaluation of crashworthiness for the cars that are made of aluminum alloys, the evaluations that consider a fracture phenomenon come to be needed because conventional aluminum alloys have low fracture strain (10 - 20%). Since an original damage & fracture material model of LS-DYNA, namely MAT_PLASTICITY_WITH _DAMAGE: MAT81 has a damage & fracture characteristic in case of compressive strain state, real collision phenomena can not be simulated in some cases. Therefore, we reviewed the damage & fracture criterion of this material model. We newly introduced some sort of a damage & fracture criterion into the MAT81 of LS-DYNA V960 in later revision and performed crashworthiness evaluations for an aluminum car using this improved damage & fracture model. This criterion has nondamage & non-fracture characteristic in compressive strain state and it is known as "Orthogonal an-isotropic (Orthotropic) damage & fracture model".