Acoustic emission monitoring of stress corrosion cracks in aligned GRP

The growth of stress corrosion cracks in aligned glass-reinforced polyester resin was monitored using the acoustic emission technique. The cracks propagated perpendicularly to the fibre direction under very low stress levels. The log-normal distribution function was applied to describe peak amplitude distributions of the acoustic emission signals produced mainly by fibre failure. It was found that the average peak amplitude of the signals is a linear function of the stress intensity K1 at the stress corrosion crack tip.