Durability aspects of adhesively bonded thick adherend lap shear joints

Applications for structural adhesive in a marine environment will generally involve much thicker adherends than used in some other industries. The effect of aging on adhesively bonded joints in a wet environment is particularly important for marine applications. A major concern is the sensitivity of the adhesive to the effects of water. The durability performance of thick-adherend steel lap joints and the bulk adhesive were investigated using accelerated aging techniques (30°C, 100% relative humidity). Various simple geometric factors are shown to affect joint performance. The removal of the spew fillet, the application of a stress and the joint orientation will all significantly influence durability performance. It was found that the water affects both the adhesive and the adhesive/adherend interfacial zone.