Numerical Investigation of the Failure Phenomena in Adhesively Bonded Joints by Means of a Multi-Linear Equivalent Plastic Stress/Strain Approach

In this work, a multi-linear material model for elastic-plastic response of ductile adhesives is proposed. Indeed, the proposed formulation allows to evaluate equivalent stress and strains to be used as material model input in FE commercial codes instead of the classical true stress and true strains. The presented model, which is capable to simulate the plasticity related phenomena and the failure event, has been implemented in the FEM code ABAQUS and used to numerically simulate the mechanical behaviour of adhesively bonded joints in traction. Several joints configurations have been considered with ductile, fragile and mix adhesives' behaviour to test the effectiveness and the range of applicability of the proposed model. Encouraging comparisons with literature experimental data demonstrates the added value of the suggested material model in predicting the failure of adhesively bonded joints.