A finite element model for impact simulation with laminated glass

A computational technique for the modelling of laminated safety glass is presented using an explicit finite element solver. Coincident finite elements are used to model the layered set-up of laminated glass: shell elements with brittle failure for the glass components and membrane elements to simulate the ultimate load carrying capacity of the PVB-interlayer. Two different approaches are considered to model laminated glass: a physical model and a smeared model. In the physical model the glass is considered as elastic/brittle and the interlayer as a hyperelastic material. For the hyperelastic description of the interlayer, we give an overview of material models, which are widely used for explicit solvers, i.e. the laws by Blatz–Ko, Mooney–Rivlin and Ogden. The obtained stress–strain curves are fitted to experimental results of the interlayer. The hyperelastic model is applied to a simple impact test demonstrating the numerical robustness. In the smeared model, we use two shell elements of equal thickness with elasto-plastic material properties to obtain an improved bending response after fracture. For validation, experimental investigations have been carried out where a spherical impactor was shot against a windscreen. The acceleration of the impactor has been measured in this test and is compared to the numerical results.