Nondestructive characterization of materials by inversion of acoustic scattering data

Abstract

In this paper, a new approach is proposed for nondestructive characterization of isotropic materials by inversion of resonance scattering data. The normal mode expansion technique is used for modelling the scattered field and the resonances of the cylinder are identified using resonance scattering theory. Genetic algorithm (GA) and simplex method are the inversion techniques used for estimating the elastic properties of the cylinder from its measured backscattered pressure spectrum. Both of these inversion techniques are capable of computing the parameter values that best fit a particular set of data. It was found that the GA is more suitable for preliminary iterations to find initial estimates of the parameters, while the simplex method is more suitable for obtaining accurate results in later stages of computations. They both showed very good convergence and the results obtained from the proposed approach were found to agree very well with those available in the literature.