Prediction of adhesive stress and strain solution and failure criterion of single lap bonded joints

Analytical models of adhesively bonded single lap joints under in-plane shear load and in-planed tension load with edge moments are developed based on shear-lag assumptions and the beam on elastic foundation model. General asymmetry of the adherends with nonlinear adhesive property is considered for the shear-loaded model. For the tension loaded model, asymmetry of the adherends is considered for the linear elastic adhesive case only. When the nonlinear adhesive property is considered (elastic-to-perfectly plastic), the adherends are simplified to the symmetric case only. Experiments and finite element models are used to directly measure the failure of the reference joint (modified ASTM D5656 specimen) and suggest a failure criterion for the analytical model based on the maximum total equivalent strain at failure. The analytical model is validated by comparing the predicted failure load with the experimentally measured failure load of ASTM D3165 specimen.