Thermal stress-induced thermoplastic composite debonding, studied by contact electrical resistance measurement

Thermal stress-induced debonding of polyphenylenesulfide from polyphenylenesulfide was studied nondestructively by measurement of the contact electrical resistance between members containing continuous unidirectional carbon fibers at 90°. The resistance increased by up to 600% upon debonding. The resistance increase was much greater than the resistance decrease during prior bonding. Debonding occurred during cooling when the pressure or temperature during prior bonding was not sufficiently high.