M. Todo et al., Strain-rate dependence of the tensile fracture behaviour of woven-cloth reinforced polyamide composites, COMP SCI T, 60(5), 2000, pp. 763-771
Tensile testing of plain-weave-cloth-reinforced polyamide composites has be
en carried out at various strain rates ranging from 1x10(-2) to 4x10(1) s(-
1) in a servohydraulic testing apparatus. Four different polyamide composit
es studied were composed of two kinds of reinforcements, carbon fibre (CF)
and glass fibre (GF), and two kinds of matrices, polyamide-6 (PA6) and modi
fied polyamide-6 (mPA6). The experimental results showed that the tensile s
trength and failure strain of the composites tend to increase with increase
in strain rate except in the case of GF/mPA6 whose fracture properties wer
e stabilized at high rates (>1x10(0) s(-1)). Damaged regions of the fractur
ed specimens were observed in order to study the micromechanisms of tensile
failure by means of polarized optical and scanning electron microscopes. T
he microscope studies showed that in the composites with the mPA6 matrix, e
xtensive microcracking occurred in the matrix and transverse threads region
prior to the final failure. The effects of strain-rate on the tensile frac
ture behaviour of these types of composite systems are discussed on the bas
is of these experimental results. (C) 2000 Elsevier Science Ltd. All rights
reserved.