Faster Simulation Approach Dedicated to Infrared Thermographic Inspection of Anisotropic Delaminated Planar Pieces

In this work, we propose an analytical model based on an approximation of the heat transfer within a part by successive and simultaneous convolution operations for the simulation of thermographic inspection (single or double-sided). Infrared thermography has already proven to be an important method for non-destructive evaluation, due to the fact that it provides information in an immediate, fast and low cost manner. The temperature distribution is approximated by its expansion on a tensor. The configurations treated by this model are laminated flat parts affected by thin delamination defects. The sources considered are lamps providing thermal excitation to the surface of the inspected part. The description of the delamination defects as thin air gaps between the layers of the part is equivalent to the introduction of a surface resistance to the thermal flow, thus allowing their treatment by the modal approach applied without additional discretization. The proposed model, although developed particularly for fibrous polymeric materials, has been generalized to be applicable to all types of materials (i.e. (an-)isotropic).