Investigation of Adherend Thickness in Thin-Ply Hybrid Laminates

The use of composite materials has been continuously increasing, hinged on its multiple advantages such as their high strength-to-weight ratio. However, this type of material is known for its anisotropic properties that may lead to premature failure of the composite laminate, stemming from the delamination of the adherend in an adhesively bonded composite joint. This study aims to study the effect of adherend thickness in uni-directional (UD) hybrid composite single lap joints reinforced by thin-ply and investigate the joint strength and failure mode. Tensile tests were carried out to evaluate the parameters mentioned experimentally, and numerical models were developed to reproduce the joint behavior. Experimental results show that adherend thickness has a minor effect on the joint strength in hybrid composite joints reinforced by thin-ply. However, a considerable change in the failure mode was observed.