Detection of impact damage in CFRP laminates

The initiation and propagation of damage in carbon fibre composites subjected to impact loading has been investigated. High velocity impact tests were conducted on a variety of stacking configurations using a nitrogen operated gas gun. The damage processes were characterised using X-radiography, ultrasonic C-scanning, optical microscopy and the deply technique. The merits and weaknesses of applying such damage detection techniques to the monitoring of impact damage in composites are discussed. The consequence of the various fracture mechanisms on residual tensile strength is also considered.