Analysis of adhesively bonded joints: a finite element method and a material model with damage

This paper deals with the derivation of a finite element (FE) method for an adhesively bonded joint which consists of two relatively thin bodies, joined by an even thinner adhesive layer. It is based on a model of the compound joint where the three bodies involved are described as material surfaces. A geometrically two-dimensional model, where the middle surfaces of the upper and lower body are represented as geometrically coinciding surfaces, is obtained. An elastic–plastic material model with damage is used for the adhesive layer, and an important implication is that the (quasi-static) propagation of the local failure zone in the adhesive layer in a structure can be simulated. Consequently, the failure load is obtained as a computational result and no failure criterion is needed. The problem is discretized, and a surface model, where only a single surface needs to be FE-meshed, is obtained. A single-lap joint is analysed and good agreement is obtained when compared to an analysis using a fine mesh with brick element. Furthermore, the failure load is computed and compared with experiments. The derived FE method opens up the possibility to efficiently model and analyse the mechanical behaviour of large bonded structures