Experimental investigation of cut-edge effect on mechanical properties of three-dimensional braided composites

Experimental characterization of the effect of cut-edge on the tensile, compressive and flexure properties in the braiding direction of the 3D braided composites is presented. The geometrical microstructure models of the uncut-edge and cut-edge composites are established for calculating the remainder lengths of braider yarns in the composites. The integrity of fiber architecture as reinforcement is destroyed for the cut-edge composites. So in order to determining the loss of the mechanical properties for the composites specimens, four schemes of cut-edge are discussed comparatively, single-edge cut on the width, single-edge cut on the thickness, both-edge cut on the width, edge cut on the thickness and width. Experimental results are coincident with the deduction based on the remainder lengths of braid yarns. The cut-edge on the width of specimen barely affects the bending properties of coupons, whereas, cut-edge on the thickness lowers the flexural modulus. The flexural modulus is reduced more when surface cut on the thickness is carrying tensile load under bending. (c) 2006 Published by Elsevier Ltd.