Stiffness behaviour due to fracture in adhesively bonded composite-to-aluminum joints I. Theoretical model

In this part of the paper, a simple generalised model for predicting the stiffness of a single-lap joint has been developed. The model considers each component of the joint as separate spring elements and, therefore, each sustains different levels of deflection. The individual deflections due to tension loading are found using basic mechanics analysis and by applying the Adams–Peppiat stress equation for adhesive bonded lap joints. The model can also predict the stiffness loss due to adhesive bond fracture by accounting for the shorter overlap length due to cracking.