Characterization of frictional behavior of fiber reinforced composites during forming: A review

Abstract

The forming process of composite laminates requires slippage to occur between adjacent plies within the lay-up and between the forming tool and the laminate until a desired final shape is achieved. Constraints imposed due to frictional stresses are often responsible for the occurrence of common forming defects, which later affect the performance of the final composite part. Hence tool-ply and interply friction characterization during composite forming has received increased attention in the last decade. Because no standardized test method exists for characterizing friction during forming, this review offers a comprehensive overview of experimental approaches and their development over the years. A detailed discussion and critical comparison of the two widely adopted test methods (pull-out and pull-through) is included. Experimental outputs and their relationship with the Stribeck curve are also addressed to analyze the effect of the forming process parameters on the frictional behavior of composites.