Performance of Adhesive Joints in an Automotive Composite Structure

This paper presents finite element analyses as well as static and fatigue performance of adhesive joints in an automotive composite structure. The automotive composite structure considered is a simply supported beam made by adhesively bonding a flat SRIM panel to the bottom of an SRIM hat section. Finite element analysis of such a beam showed the presence of significant peel stresses in the adhesive layer. Static and fatigue tests were then conducted with transverse tensile loads on adhesively bonded hat sections to determine the failure load in the peel direction. Finite element analysis of the transverse tensile loading condition identified the critical stresses in the adhesive and the failure mode expected in such joints. This study also examined the usefulness of combining adhesive and bolts to improve the joint performance.