Effect of Through-Thickness Stitching on the Fatigue Life of Composite Single-Lap Joints

An exploratory experimental evaluation has been undertaken to investigate the effect of through-thickness stitching on the fatigue life of composite single lap joints. Balanced single lap joints were considered, and the lay-up for the adherends was (0/±45/90)^sub s^ Specimens were stitched transversely and through-the-thickness with Kevlar^sup ®^ thread in a zigzag pattern and were manufactured using the resin transfer moulding (RTM) technique. Preliminary experimental results have indicated that stitches remain intact when the crack starts growing from either side of the overlap. This consequently imparts a significant improvement in the fatigue life of stitched versus unstitched counterparts.[PUBLICATION ABSTRACT]