Dynamic tensile response of a carbon fibre reinforced LCP composite and its temperature sensitivity

Abstract

The tensile mechanical behaviour of a short carbon fibre filled liquid crystalline polymer (LCP) composite (30% fibre weight), Vectra A230, was examined under static extension (strain rate = 10-2 s-1) and dynamic loading (strain rate = 400 s-1), at three temperatures (55°C, 25°C and -10°C). Dynamic tension was applied using a pendulum-type tensile split Hopkinson bar device. Specimens fabricated according to both the mould flow and transverse directions were tested. The stress-strain curves at various strain rates and temperatures were determined and found to be sensitive to strain rate as well as temperature for both types of specimens. With reference to the properties of pure LCP, mechanical anisotropy and fibre reinforcement effects were characterised and are discussed. Failed specimens were observed using an optical microscope. Deformation and failure mechanisms in the microstructure of the LCP composite were studied to understand the effects of strain rat e and temperature on material strength and failure strain.