Abstract

Adhesive joints offer several advantages over traditional joints (welds, rivets), including reduced weight, excellent surface finish and the ability to bond dissimilar materials (i.e. metal to polymer). Adhesive technology is particularly relevant to applications incorporating lightweight materials such as composites and aluminium, which are of increasing interest in the transportation industry. Adhesives are finding applications in the naval industry, but adoption is limited by an incomplete understanding of the mechanics of adhesive joints. How do failure strength, toughness and damage tolerance vary with the thickness of an adhesive layer? Can these properties be improved, or varied to meet specific design requirements? To address these questions, a variety of quasi-static tests have been conducted on adhesive joints composed of aluminium and a rubber-like MS-polymer adhesive. Butt joints and double-lap shear joints were studied and the observed failure mechanisms are discussed. Joints with novel interface geometries, such as “square wave” periodic interlocking interfaces, have also been studied. A design tool has been developed which predicts the peak strength and work of fracture of square wave interfaces as functions of geometric parameters. A performance map is presented, which can be used to guide the design of future interfaces according to design requirements.