Effects of Young's modulus of epoxy resin on axial compressive strength of carbon fibre

Abstract

Using epoxy resins with various molecular weight between cross-linkings, attempts have been made to estimate the fibre axial compressive strength of pitch-based graphitized fibre, and the effect of Young's modulus of epoxy resins on compressive strength was investigated. The estimated compressive strength of fibre decreases with increasing temperature. This decrease in compressive strength may be accounted for by a decrease in the radial compressing force due to a decrease in the residual thermal stress. There is a linear relationship between the estimated compressive strength and radial compressive force in a temperature range from room temperature to 80 °C. The estimated compressive strength of the fibre increases with increasing Young's modulus of epoxy resins. In order to realize reinforcing fibres with a higher compressive strength, it will be necessary to use a resin matrix with a higher modulus.