Inversion of Infrared Nondestructive Testing with Evolution Algorithm

Abstract

The technology of infrared nondestructive testing is an important method to detect where the defect is, and its order of severity. In pulse heating stage, obviously there is also temperature difference between defect area and no defect area. So this paper uses temperature difference between defect area and no defect area in the pulse heating stage, according to 1-D transient heat conduction model of finite thickness defect slab under Neumann boundary condition and heat conduction equation, builds a least-square formula to inverse the depth of defect area in the defect slab with evolution algorithm. The results show that this evolutionary algorithm is reliable, and it has only small errors, and is especially suitable for detecting large defect area. To do the more accurate detection, it still needs to find a new data processing method for infrared nondestructive testing from starting with three-dimensional heat conduction inverse problem.