AN INVESTIGATION INTO THE EFFECTS OF FABRIC ARCHITECTURE ON THE PROCESSING AND PROPERTIES OF FIBER-REINFORCED COMPOSITES PRODUCED BY RESIN TRANSFER MOLDING

The use of resin transfer moulding (RTM) as an economic and efficient means of producing high performance fibre-reinforced composites is cri tically limited by the permeability of the fabrics employed. Commercia l fabrics are available where the architecture of their reinforcement is designed to cluster the fibres, giving higher permeabilities than c onventional fabrics. This has been shown to improve processing times, but there is evidence that such clustering is detrimental to the mecha nical performance of the resulting composite materials. The objective of this work was to relate variations in permeability and mechanical p erformance to differences in composite microstructure. This was achiev ed by producing carbon/epoxy plates of different weave styles by RTM i n a transparent mould. The progress of the resin was recorded by a vid eo camera during injection, and the images were processed by a frame-g rabbing computer, permitting the permeabilities of the fabrics to be c alculated. Further plates were manufactured using the same fabrics, an d sectioned for microstructural image analysis and interlaminar shear strength (ILSS) testing to CRAG standards. Relationships were sought b etween measured permeabilities and finished microstructures using a Qu antimet 570 automatic image analyser. It has been shown that variation s in permeabilities and mechanical properties can be related to observ ed differences in the microstructure. (C) 1997 Elsevier Science Limite d.