Numerical Study of PVB Laminated Windshield Cracking Upon Human Head Impact

The crack pattern in a PVB laminated windshield upon head impact is of considerable interest because it contains important information on energy mitigation, pedestrian protection, and accident reconstruction. We carry out a systematic numerical study based on the extended finite element method (XFEM), to investigate the effects of various material and system variables, including the impact speed, effective head mass, PVB interlayer material thickness and property, windshield curvature, aspect ratio and size, boundary constraint, impact angle and off-center impact, on the parameters characterizing the resulting crack pattern, i.e. the crack length, crack angle and circumferential crack shape. General relations bridging these variables and parameters are established via extensive simulations, and the effect and mechanism of each governing factor are elucidated. The findings will shed some light on accident investigation, crashworthiness, and vehicle safety design, on the basis of a systematic understanding of the PVB laminated windshield cracking subject to human head impact.