Meshless approach to material plasticity in adhesive joints

Abstract

For an efficient use of adhesive joints, reliable prediction techniques should be made available to the designer. Simulation is usually accomplished by the Finite Element Method (FEM). However, in adhesive joints, the adhesive thickness is much smaller than that of the adherends, thus requiring a refined mesh to produce good results. Linked to this, the adhesive has to withstand high strains, causing mesh distortion and making difficult to attain solution. In these cases, meshless methods can be a good alternative, although these are not sufficiently validated yet. This work aims to implement the von Mises (vM) and Exponent Drucker-Prager (EDP) criteria into a user-built meshless method software based on the Radial Point Interpolation Method (RPIM), for the strength prediction of adhesively-bonded single-lap joints (SLJ). Validation with experiments is undertaken for a medium-ductile adhesive (Araldite® 2015) with varying overlap lengths (LO). Stress and strain distributions were plotted in the adhesive layer, and the failure load (Pm) was assessed by continuum mechanics failure criteria. The meshless method showed to be promising in predicting the behavior of bonded joints, although limitations were found by using continuum mechanics criteria.