Induction thermography on CFRP and the role of anisotropy

Experiments were performed by induction thermography on carbon fibre reinforced plates. Uni-axial, bi-axial materials as well as woven fabric were studied. The uni-axial material was investigated as a function of the fibre orientation angle and showed heating far away from the inductor and heating patterns with local minima. The occurrence of minima was explained by induction current cancellation effects. The experimentally measured thermal contrast patterns were confirmed by the results of numerical simulations. Fiber breakage could be detected better by induction thermography than by optically excited thermography