Finite element analysis of bonded joints in composite materials

The paper presents the results of several numerical analyses carried out with aim to investigate the stress fields and simulate crack propagation in composite joints, thus providing tools for the development of life prediction methodologies. Single lap bonded joints with different overlap length and corner geometry were studied. In view of predicting static strength and fatigue crack initiation, stress distributions and generalised stress intensity factors near the singular zones were evaluated on un-cracked FE models by geometrically linear analyses. For simulating the crack growth, the Strain Energy Release Rate trends as a function of the crack length were estimated by using Virtual Crack Closure Technique. In this case, results obtained from geometrically linear and non-linear analyses are compared, being the latter those providing more reliable results.