Cohesive zone modeling for adhesives

Adhesives are very widely used in industry. In each application field, the adhesive that is used must fulfill specific requirements. Adhesive types can be classified for instance by their (thermo-) mechanical properties, their machining or their curing conditions. This paper describes, by way of example, the characterization criteria for structural and flexible adhesives with respect to differences in their mechanical properties under various test conditions such as loading rate or environmental temperature. For further increased industrial application of adhesives, for example to improve the crash performance of cars, the ability to predict the mechanical behavior by numerical simulation is required. Cohesive Zone Models (CZMs) are well suited for modeling adhesives. In this paper a tri-linear, strain-rate dependent CZM is presented. This model is compared to the bi-linear, strain-rate independent model implemented in ABAQUSTM. The parameters of these models are determined by direct testing of tensile bulk, tapered double cantilever beam, lap-shear and T-peel specimens. The model validation was carried out by comparing experiment results and simulations for a Ushaped specimen under different loading velocities. The application of these CZMs in offset crash test simulations is presented and compared to experimental data