Deformation and failure modelling of high strength adhesives for crash simulation

The deformation and failure mechanisms of toughened high strength adhesives used in the automotive industry are very complex and require advanced numerical models for crashworthiness simulation. The theoretical background of two new modelling approaches for thin adhesive layers is presented: firstly, a simplified elastic damaging node-to-element tied interface model approach for convenient and efficient modelling, and secondly a detailed modelling approach for improved accuracy using an elasto-viscoplastic solid element representation of the adhesive layer. The material model parameters required for both approaches are determined by a comprehensive set of experiments, including quasi-static and dynamic adhesive coupon testing, fracture toughness testing, and quasi-static tension/shear (and combined) testing of thin adhesive layers. A more complex adhesively joined assembly of two aluminium extrusions subjected to quasi-static (QS) and dynamic loading serves as the final validation example for both modelling approaches. Good agreement of experiments and numerical predictions was observed for both modelling approaches.