Crack analysis in PVB laminated windshield impacted by pedestrian head in traffic accident

A damage-modified nonlinear viscoelastic constitutive relations model of PVB laminated windshield is suggested based on updated Lagrangian method to study the crack evolutions on windshield plate subject to pedestrian head. After verified by a classical example, the constitutive relations are implemented into FEA software. With proper material properties, the FEA model describing the pedestrian head impact with vehicle windshield in traffic accident is established. The computation results of FEA model and classical Hertzian pressure model are in good agreement. Moreover, the FEA model is used to analyse the internal stresses. Shear stress, compressive stress and tensile stress are main causes of plastic deformation, radial cracks and circumferential cracks, respectively. Internal stresses decrease as the distance away from the impacted point increases. In addition, parametric studies were carried out to study the effects of Poisson's ratio and impact velocity.