Structural performance of thick adherend steel-composite adhesive joints

The aim of this paper is to assess the performance of two types of bonded joint with reference to specific design concepts, materials and application for hybrid steel-composite panel construction. The joints are (a) laminate-to-frame connections and (b) butt joints between adjacent laminates. The objectives are (a) to understand the structural behaviour, (b) to determine the failure mechanisms and (c) to determine the effect of the joint geometry on the strength of the bonded joints. The materials used for these joints were polyester-glass composite laminates, mild steel sections and epoxy adhesives. The paper describes the results from mechanical testing and numerical analyses for these joints. A key conclusion is that structural epoxy adhesives provide substantial joint strength to composite panels even though the composite uses low-strength resin. The joint strength is governed by adherend geometry.