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.