Abstract (Invited)

Inverse Problems in Nonlinear Wave Modulation Spectroscopy

A.M.Sutin (Stevens Intstitute of Technology, Hoboken, NJ, USA and Institute of Applied Physics RAN, Nizhny Novgorod, Russia)

e-mail: asutin@stevens-tech.edu

Nonlinear Wave Modulation Spectroscopy (NWMS) is a novel Nondestructive Testing technique based on ultrasonic probe signal modulation by low frequency vibration, i.e., nonlinear mixing of the probe and impact signal. The modulation manifests itself as the side-band (intermodulation) components in the spectrum of the received ultrasonic signal. Numerous tests carried out in Los Alamos National Laboratory, Russian Institute of Applied Physics and elsewhere have demonstrated the high sensitivity of NWMS methods for crack and damage detection in different materials and components, including: metal parts, composites, concrete, polycarbonate, plexiglass, sandstone, bones, etc. The previous research was primarily qualitative and our recent work has been devoted to development of quantitative approaches applying NWMS. 1. The crack location can be obtained by application of Impulse Modulation and Mode Tomography techniques. The results of the crack location technique by using Impulse Modulation technique are presented. Direct and inverse problems for Mode Tomography technique are discussed. 2. NWMS application for crack parameter determination require development of the crack models and models of the damaged material. Possible different crack models and cracked media are presented.

Section : 3