Benchmarking of three-dimensional finite element models of CFRP single-lap bonded joints

One of the challenges in the analysis and design of bonded joints is the evaluation of the stress and strain fields at the adhesive layer. Experimental work can be carried out in the laboratory in order to identify the ultimate load value, but numerical methods based on finite element models can be very useful in describing the stress and strain responses for each load step. In this work, the consideration of the accuracy of finite element discretizations used to simulate the joint is under debate. A parametric study aimed to compare the performance of several modelizations of a joint made of two CFRP adherends bonded by a layer of epoxy film adhesive will be presented, in order to help in the development of modelling guidelines. All the simulations were conducted with three-dimensional meshes and geometrical nonlinearity was considered, requiring extensive computation time. Results obtained with different mesh sizes and element types are compared with the available experimental data and all the information is related with the computational cost, allowing decision making about which model to use in every design situation.