Application of Resonant Ultrasound Spectroscopy to Inhomogeneous Materials

Abstract

Abstract : Resonant Ultrasound Spectroscopy (RUS) has been used successfully to determine the elastic properties of single crystal and homogeneous materials. We have attempted to answer the following question. Under what conditions is RUS a useful tool for determining the moduli of macroscopic, inhomogeneous samples. We concentrated on identifying a sample geometry that will maximize success with RUS. The work consisted of numerical modeling of sample resonances under varying conditions, and empirical testing of rock samples. Numerical modeling and empirical testing indicate that RUS is a viable technique for characterizing the average isotropic elastic moduli of inhomogeneous materials, although larger RMS errors can be expected than for single crystal materials. Success with RUS can optimized by ensuring that the sample size is large compared to the scale of inhomogeneity and by using a high aspect ratio parallelepiped sample.