A non-linear hyperelastic foundation beam theory model for double cantilever beam tests with thick flexible adhesive

Flexible adhesive joints, with adhesives of very low elastic modulus and very large failure deformation, are of special interest in industrial applications. Nevertheless, there is a lack of effective models for predicting their behaviour for structural applications. Existing methods developed for stiff compressible adhesives are not able to accurately capture the nonlinearities present on a thick flexible bondline. This paper presents a new analytical model for the simulation of a flexible adhesive bonded joint in a double cantilever beam (DCB) setup. Using the concepts of elastic foundation beam theory and developing them for a more general non-linear hyperelastic foundation case, a semi-analytical model is proposed. The effectiveness of the model, with respect to other approaches shown in the literature, is compared against experimental results for Krafft's flexible adhesive SILKRON POLYMER H-100. The hyperelastic foundation model accurately predicts the load-displacement response of the adhesive.