Finite-Element Analysis and Experimental Study: the Effects of Stacking Sequence of Stitched Layers on Tensile Properties of Glass/Epoxy Composites

Abstract

This study aimed to investigate the effects of stitch angle, stitch density, and stacking sequence of stitched layers on the tensile behavior of eight-layer glass/epoxy composites. For this purpose, reinforcement glass fabrics were stitched with a stitch pitch of 4 mm at three stitch densities of 2, 3, and 4 per cm² and five different stitch angles of (0 \(^\circ\)), (45 \(^\circ\)), (0 \(^\circ\),90 \(^\circ\)), (± 45 \(^\circ\)), and (0 \(^\circ\), 90 \(^\circ\), ± 45 \(^\circ\)). Different layups of unstitched and stitched layers (2 and 4 layers of stitched glass fabrics at angles of 0 \(^\circ\)) were used to study the effect of stacking sequences of stitched layers. The results indicated that the tensile strength of the eight‐layer stitched composite compared to the unstitched sample can be increased by up to 29.4%. Accordingly, in cases where stitching all layers is not simultaneously feasible, employing stitching on multiple layers instead of all layers can be an effective solution. Using this method, a 14.5% increase was observed in the tensile strength of the stitched composites compared to unstitched sample. The comparison of the obtained results revealed an acceptable agreement between the experimental results and the numerical finite-element analysis using ANSYS software.