ELECTRICAL-RESISTANCE MEASUREMENT TECHNIQUE FOR DETECTING FAILURE IN CFRP MATERIALS AT HIGH-STRAIN RATES

A new electrical resistance technique is considered for detecting failure in balanced (+/- theta(s)) angle-ply carbon fibre reinforced plastic materials (CFRP) under high strain-rate tensile testing. The electrical conductivities of balanced angle-ply laminates are measured for a number of angles and the results are compared with the conductivities of an off-axis lamina. The variation of electrical resistance of angle-ply CFRP tubes during expansion, when subjected to internal explosive loading pulses, is monitored. The change of the resistance of the tubes is compared with the deformations as measured by conventional strain-gauges. The method shows promise in detecting the instant of composite failure.