Modelling the cyclic inelastic behaviour of a dissimilar metal/composite bonded joint at low frequencies

ABSTRACT The present paper is concerned with the investigation of the inelastic behaviour observed in load-unload cyclic tests performed at 50°C in single lap joints composed of a polyurethane based composite reinforced with fibreglass bonded to an ASTM A1020 steel substrate using an epoxy adhesive. The experiments presented in this research show that the inelastic behaviour of the joint is strongly dependent on the load frequency, eventually leading the structure to exhibit a progressive deformation when submitted to load-unload cyclic loading. The main goal of this study was to propose a preliminary rate-dependent mechanical model capable to describe the cyclic inelastic behaviour for an arbitrary load-unload history at low frequencies and a reasonable agreement was obtained between the experimental results and the model predictions.