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.
Bibliographical noteAcknowledgement: This work is financially supported by National Natural Science Foundation of China (NSFC 10972122), State Key Laboratory of Automotive Safety & Energy, Tsinghua University (ZZ0800062) and Doctoral Fund of Ministry of Education of China (20090002110082). Y. Li and X. Chen appreciate the founding from Tsinghua University under the International Cooperation Project. J. Xu also appreciates China Scholarship Council (CSC) to financially sponsor his study at Columbia University through a joint Ph.D. program. X. Chen is supported by the National Science Foundation (CMMI-0643726) and NSFC (50928601).
- PVB laminated windshield
- Extended finite element method
- Low-speed impact
- Crack pattern