Solution of Transient Temperature Field for Thermographic NDT Under Joule Effect Heating

Conducting infrared thermographic nondestructive testing (NDT) by the internal heat generated by Joule effect of components is a new heating approach for flaw detection. Due to the combination of electric field and thermal field, the irregular geometric boundary and the complicated internal heat source distribution, the theoretical solution of transient temperature field is very difficult. Nowadays numerical solution by FEM and FDM is mainly applied. By adopting certain assumptions, this paper presents a method to obtain the approximate temperature field by using Green's function, and gives the solution of a two-dimensional rectangular field including 7 circular flaw. By contrast, the result tallies with the FEM results well.