An investigation on strain/stress distribution around the overlap end of laminated composite single-lap joints

The damages of laminated composite single-lap joints often begin from their overlap ends because strain/stress concentrations often occur at the overlap ends. This paper presents the results of a combined experimental and finite element (FE) investigation on the strain/stress distributions around the overlap ends of laminated composite single-lap joints. Digital image correlation (DIC) technique is used to measure the strain fields near the overlap ends. A three-dimensional geometrically nonlinear FE model based on the submodel technique is developed to predict the deformation of single-lap joints. A reasonable agreement is achieved between the results from experimental measurements and FE analysis. Additionally, some FE models are built to investigate the effects of the mesostructures at the overlap ends on the stress concentrations around the overlap ends.