Resin impregnation and prediction of fabric properties 287 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 早口88号将导导8品88只品品8 fibre orientation (degrees) 9.1 Typical variation of modulus with fibre orientation. thermosetting epoxy matrices which offer low shrinkage during processing, excellent adhesion to the fibres,good property balance,particularly mechanical to electrical performance,and ease of fabrication.They also have a good heat resistance and stability over a wide range of environ- mental conditions. n Typical fibre loading in high-performance composite materials is 60-65% by volume (65-70%by weight).Carbon fibres have a coefficient of thermal expansion which is a slightly negative sequence.Production of composites from fibres with a fairly broad range of coefficients of thermal expansion values permits the manufacture of components with an almost zero coeffi- cient of thermal expansion.This feature can be exploited,particularly in air- craft,to hold critical instrumentation in a precise position as the composite properties of the supporting component can be tailored specifically at the design stage.For particular components this demonstrates the potential to design or engineer specific properties into materials to meet the perfor- mance requirements and hence optimize the structural design. In comparison with steel and aluminium,carbon fibre composites are lighter,have lower thermal conductivity,are stiffer and stronger and have superior fatigue resistance.A summary of the typical properties of high strength and high modulus carbon fibre composite materials in an epoxy resin is shown in Table 9.1.The marked differences in properties between uni-directional(0),transverse(90)and the quasi--isotropic(0°，±45°，90) fibre orientations should be noted.The high-modulus fibre composite datathermosetting epoxy matrices which offer low shrinkage during processing, excellent adhesion to the fibres, good property balance, particularly mechanical to electrical performance, and ease of fabrication. They also have a good heat resistance and stability over a wide range of environ￾mental conditions. Typical fibre loading in high-performance composite materials is 60–65% by volume (65–70% by weight). Carbon fibres have a coefficient of thermal expansion which is a slightly negative sequence. Production of composites from fibres with a fairly broad range of coefficients of thermal expansion values permits the manufacture of components with an almost zero coeffi- cient of thermal expansion.This feature can be exploited, particularly in air￾craft, to hold critical instrumentation in a precise position as the composite properties of the supporting component can be tailored specifically at the design stage. For particular components this demonstrates the potential to design or engineer specific properties into materials to meet the perfor￾mance requirements and hence optimize the structural design. In comparison with steel and aluminium, carbon fibre composites are lighter, have lower thermal conductivity, are stiffer and stronger and have superior fatigue resistance. A summary of the typical properties of high strength and high modulus carbon fibre composite materials in an epoxy resin is shown in Table 9.1. The marked differences in properties between uni-directional (0°), transverse (90°) and the quasi-isotropic (0°, ±45°, 90°) fibre orientations should be noted. The high-modulus fibre composite data Resin impregnation and prediction of fabric properties 287 9.1 Typical variation of modulus with fibre orientation. RIC9 7/10/99 8:32 PM Page 287 Copyrighted Material downloaded from Woodhead Publishing Online Delivered by http://woodhead.metapress.com Hong Kong Polytechnic University (714-57-975) Saturday, January 22, 2011 12:31:57 AM IP Address: 158.132.122.9