Numerical simulations of impact fracture behavior of an automotive windshield glazing: An intrinsic cohesive approach

As an important component of a vehicle, the automotive windshield glazing normally consists of two glass sheets bonded with one polyvinyl butyral (PVB) film. In the context of pedestrian-vehicle accidents, the impact cracking mechanism of the windshield is conductive to pedestrian safety protection and traffic accident reconstruction. The purpose of this paper is to validate the capacity of the intrinsic cohesive zone model (CZM) in impact fracture simulations of a windshield. A windshield finite element (FE) model is established, where cohesive elements are inserted into all the common faces between glass hexahedral finite elements. The fracture behavior of a windshield impacted by a standard adult headform impactor is simulated with the commercial explicit finite element code LS-DYNA. Numerical simulation results are validated by comparison with the corresponding experimental outcomes. For comparison, additional simulations have been performed by the widely used element deletion method (EDM) with a plasticity strain failure criterion. Simulation results show that the intrinsic CZM is more suitable to capture the impact failure characteristics of windshield. Finally, the effects of the glass cohesive strength, mechanical properties of PVB and interfacial adhesion on the impact fracture behavior of the windshield are investigated.