A nonlinear guided wave NDE and tomography for micro damage detection and imaging

Ultrasonic guided waves have been of great interest to safety and maintenance related engineers and scholars because they render a number of practical merits over a conventional local point-by-point inspection techniques. They include possibilities of inspecting a large scale structural integrity at a distance from a fixed transducer position without scanning and improving monitoring sensitivity with a variety of mode choice and data analysis schemes. While most of earlier efforts in the guided wave SHM (Structural Health Management) and NDE (Nondestructive Evaluation) were confined to initial screening applications of pressure vessels and pipes to narrow down the follow-up inspection, recent progress in the related area shows some promising feasibility even for much more challenging tasks including early stage damage detection, quantitative imaging of hidden damage zone and non-contact based inspection scheme. This paper addresses the forwarding steps of guided wave SHM and NDE recently accomplished introducing the key concepts of each technique for near future applications in a variety of industry including power industry.