Further Development of the Simulation of Sonic IR Imaging of Cracks in Metals with Finite-Element Models

摘要

Sonic IR imaging, which combines infrared imaging and ultrasound excitation, as a relative new member of the NDE family, has been drawing wider and wider attention due to its fast, wide area inspection capability. In our previous presentations and publications, we have described the application of acoustic chaos to Sonic IR imaging and have provided experimental illustrations as well. In addition, we have described realistic finite-element models that simulate the heating of cracks in metals by both chaotic and non-chaotic sound. These models allow for both friction and plastic deformation as sources of heating. In this paper, we present our further study on the physical mechanisms that are responsible for the advantages of chaotic sound for Sonic IR crack detection. Using finite-element analysis, here we will present theoretical explanations, both for the origin of the chaos, and for the mechanisms responsible for the chaotic enhancement of crack detection.