The dynamic fracture behavior of PVB laminated glass during impact has been studied by both theoretic and finite element approaches. To make the analysis of cracking on PVB laminated glass more accurate and direct, high-speed photography method is introduced in this paper. Different crack patterns as well as their sequences of appearance are visualized. Finally, typical crack is measured in order to obtain important fracture characteristics such as crack velocity and acceleration.

In this paper, energy absorption characteristics of PVB laminated windshield subject to human head impact are studied. SHPB method is carried out to obtain the constitutive relationships of PVB laminated glass in dynamic behavior. With the SHPB results embedded, finite element simulation is used to study the dynamic behavior of PVB laminated windshield. In particular, energy absorption characteristics are investigated. Two parameters for measuring the energy absorption property of windshield are suggested, i.e. loss of head velocity and HIC value and a parametric study is carried out to see the effect of impact velocity and impact position. Results can shed lights on the research of energy absorption capability of PVB laminated windshield.

Pedestrian-vehicle accident without road marks has long been a headache to accident investigators. This paper suggested a new method with the application of fracture mechanics to estimate impact speed in pedestrian-vehicle. Firstly, a windshield crack propagation model based on the crack initiation model put forward by Freund [1] is established. In the model, crack bluntness coefficient is an unknown parameter, depending on various factors, so speed domain is then divided into five intervals and sample real-world accident cases are employed to the calibrate crack bluntness coefficient in different speed intervals. Further, fourth-order Runge Kutta’s method is used to solve the differential equation. Five additional real-world accident cases are then employed to verify the accuracy of the model. Results show good agreement between the model results and the real impact speeds. Finally, the advantages and limitations of this method are discussed.