Detection of delamination in thermoplastic CFRP welded zones using induction heating assisted eddy current testing

This paper presents a new eddy current method named induction heating assisted eddy current testing (IHAET) for detecting delamination in thermoplastic CFRP welded zones. In IHAET, weld part is heated by induction heating to produce a high temperature spot on delamination. Electrical conductivity of the high temperature spot is larger than that of intact zones due to temperature dependence of conductivity of carbon fibers and its location can be identified by multiple pickup coils. Experimental studies carried out on CF fabric/PPS showed the validity of IHAET and detected 450 mm2 delamination 2 mm away from the surface by using a statistical diagnosis.