Some Inversion Problems in Nondestructive Evaluation
Nondestructive evaluation (NDE) is to materials and structures what CAT scanning is to the human body---an attempt to look inside without opening the body. It is in nature an inversion problem. While such problems present a formidable mathematical challenge, sophisticated new models and software are beginning to yield useful results. In this paper we discuss the solution of several inversion problems using the eddy-current volume-integral code, VIC-3D1. These problems, the reconstruction of flaws in steam-generator tubing, the determination of metallic plate thicknesses, and the reconstruction of conductivity profiles versus depth in metallic materials, are typical of the application of eddy-current NDE to process control and in-service inspection.