Resonant ultrasound spectroscopy and some extensions

Abstract

Resonant ultrasound spectroscopy (RUS) is a method in which knowledge of the shape, mass, and some natural frequencies of a sample of solid material may be used to determine the elastic properties of the material. Customarily, the natural frequencies are measured by driving the sample with a sine wave in one transducer and monitoring the sample's response with a second transducer; when the frequency of the drive is swept through a natural frequency, a tuning curve is measured, from which the natural frequency and a quality factor may be determined. Usually, a Rayleigh-Ritz method involving rectangular parallelepiped or cylindrical sample shapes and polynomial basis functions is used to analyze the data to determine the elastic properties. This talk will discuss the customary method and some extensions, including: 1) overcoming a limitation that for some problematic materials (e.g., elastomers), the method can measure only one elastic constant accurately; 2) modifying the method to include piezoelectric materials; 3) overcoming the inaccuracy of the method for samples having sharp interfaces between different materials.