Hybrid and adhesively bonded joints with dissimilar adherends: a critical review

This paper reviews the reported literature on dissimilar (non-matched adherend) adhesively bonded joints (ABJs), currently used bonding processes, and the mechanisms by which these types of joints fail when subjected to structural loading and environmental conditions. Additionally, approaches to improve the performance of dissimilar ABJs, through geometrical and material modifications, are also discussed. Many studies have reported on the strength and failure behaviours of adhesively bonded joints, but of those, few have reported on the performance of dissimilar ABJs. Unlike matched ABJs, the absence of accepted design approaches for dissimilar ABJs arises from their inherent inhomogeneity, which introduces complexities in load transfer mechanisms, in the distribution of stresses through the joint, and in the mechanisms by which the joint ultimately fails. Several authors have proposed approaches to improve the performance of adhesively bonded joints, variously through geometrical or material modification means, but there remains unmet research needs to better understand novel dissimilar ABJ designs.