Research on finite element analysis of the infrared grating lock-in thermal imaging method
Infrared grating lock-in thermal test is a kind of infrared nondestructive testing methods with the combination of grating incentive and infrared lock-in thermal technology. This method is adopted to realize the vertical crack detecting inside the components. There is no related research up to now by using a grating which changes according to sine rule to the defects detection. In this paper, the numerical simulation of this method is carried out, and the finite element analysis process is introduced in detail. Results show that the choice of appropriate detection frequency and level speed is the key for the infrared grating lock-in method to detect. Our study verifies the feasibility of effective detection for superficial cracks in the film.