Three-dimensional nonlinear analysis of adhesively bonded lap joints considering viscoplasticity in adhesives

The paper presents three-dimensional (3D) viscoplastic analysis of adhesively bonded single lap joint considering material and geometric nonlinearity. The constitutive relations for the adhesive is developed using a pressure dependent (modified) von Mises yield function and Ramberg–Osgood idealization for the experimental stress–strain curve. The adherends and adhesive layers are modelled using 20 noded solid elements. The overall geometry of the lap joint, the loading and the boundary conditions have been considered both according to the ASTM testing standard as well as from those adopted in earlier investigations. Materially and geometrically nonlinear finite element analysis have been carried out on several joint configurations. However, observations have been made in particular on peel and shear stresses in the adhesive layer, which provides useful insight into the 3D nature of the problem.