EFFECT OF THE FREE-EDGE FINISHING ON THE TENSILE-STRENGTH OF CARBON-EPOXY LAMINATES

High productivity can be achieved in the fabrication of composite laminates if molded edges are used. In this work, the fabrication process of laminates with this type of edge finishing is described. The stacking sequence effect for laminates with molded edges is experimentally studied and compared to that of laminates with machined edges. The tensile strengths of five different laminates fabricated with carbon/epoxy unidirectional tape and woven fabrics were measured. It is shown that the strength of laminates with molded edges is about 10% lower than that of laminates with machined edges but less sensitive to stacking sequence. The presence of small pockets of pure resin near the free edge of laminates with molded edges causes a reduction in the tensile strength. The stacking sequence effect may be very pronounced for laminates with woven fabric layers and machined edges.