Modeling Fracture in Laminated Automotive Glazing Impacted by Spherical Featureless Headform

Laminated glass consisting of two soda lime glass plies adhered by a polyvinyl butyral interlayer (PVB) is used for automotive glazing. This paper describes the application of a dynamic, nonlinear finite element method to investigate the failure modes of a laminated glass subjected to low-velocity impact with a spherical headform. Crack type, crack location and crack initiation time are evaluated using the maximum principal stress and J-integral criterion. Failure occurred due to flexural stresses and not bearing stresses. The first crack always initiated at the center of the outer impacted ply and PVB interface, and later on the exterior surface of the inner ply. The PVB thickness and velocity of impact had little or no effect on the first crack initiation.