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.