MEASUREMENT OF THE TRANSVERSE MECHANICAL-PROPERTIES OF HIGH-PERFORMANCE FIBERS

The measurement of the transverse modulus of single fibres having a diameter of 5-15-mu-m has become possible by the development of a new instrument. An account is given in this paper of an investigation of some typical high-performance fibres for their transverse modulus and their fibre strength in transverse compression. The high-performance fibres studied were aramid fibres having different longitudinal moduli, pitch and PAN carbon fibres, also of different modulus values, and some other reference fibres. These fibres had strong anisotropy in the longitudinal and transverse directions to the fibre axis, and there was correlation between the two directional moduli. The transverse strength by the two directional moduli. The transverse strength by compression was also investigated for these fibres. Organic fibres of highly oriented polymers showed a ductile property in transverse compression and had a yielding stress, but carbon and ceramic fibres showed brittle behaviour in compression. A correlation between the yield stress or breaking stress and the transverse modulus was found for these fibres.