This first procedural guide to RUS, Resonant Ultrasound Spectroscopy offers a clear step-by-step tutorial, from developing a preliminary set of resonances to final determination of moduli. The book also contains intermediate computer outputs showing where mistakes are made, how to spot them, and how to remeasure to correct problems. Also a complete reference to the language of RUS, this book is full of clear explanations of every variable, concept, and hard-to-find term currently in use.

This paper describes resonant ultrasound spectroscopy (RUS) as a powerful and established technique for measuring elastic constants of a material with general anisotropy. The first step of this technique consists of extracting resonance frequencies and damping from the vibrational frequency spectrum measured on a sample with free boundary conditions. An inversion technique is then used to retrieve the elastic tensor from the measured resonance frequencies. As originally developed, RUS has been mostly applicable to (i) materials with small damping such that the resonances of the sample are well separated and (ii) samples with simple geometries for which analytical solutions exist. In this paper, these limitations are addressed with a new RUS approach adapted to materials with high damping and samples of arbitrary geometry. Resonances are extracted by fitting a sum of exponentially damped sinusoids to the measured frequency spectrum. The inversion of the elastic tensor is achieved with a genetic algorithm, which allows searching for a global minimum within a discrete and relatively wide solution space. First, the accuracy of the proposed approach is evaluated against numerical data simulated for samples with isotropic symmetry and transversely isotropic symmetry. Subsequently, the applicability of the approach is demonstrated using experimental data collected on a composite structure consisting of a cylindrical sample of Berea sandstone glued to a large piezoelectric disk. In the proposed experiments, RUS is further enhanced by the use of a 3-D laser vibrometer allowing the visualization of most of the modes in the frequency band studied.

Resonance Acoustic Spectroscopy deals with the analysis of waves generated in an elastic body by a plane harmonic acoustic wave. It is the first monograph to treat new analytical and experimental methods for the investigation of the excitation, propagation and re-radiation of elastic waves in solid, thick-walled and thin-walled elastic scatterers.The material is presented systematically, comprising the formulation of the problem, method of solution, algorithm, computation and analysis. A large number of computational results are given in the form of modal resonances, form functions, dispersion curves and acoustic spectrograms. Particular attention is paid to the interpretation of the solutions.

This volume provides an overview of modern acoustical techniques for the measurement of mechanical properties. Chapters include Fundamentals of Elastic Constants; Point Source/Point Receiver Methods; Laser Controlled Surface Acoustic Waves; Quantitative Acoustical Microscopy of Solids; Resonant Ultrasound Spectroscopy; Elastic Properties and Thermodynamics; Sound Speed as a Thermodynamic Property of Fluids; Noninvasive Determination of Sound Speed in Liquids; Introduction to the Elastic Constants of Gases; and Acoustic Measurement in Gases.

A resonant ultrasound spectroscopy method provides a unique characterization of an object for use in distinguishing similar objects having physical differences greater than a predetermined tolerance. A resonant response spectrum is obtained for a reference object by placing excitation and detection transducers at any accessible location on the object. The spectrum is analyzed to determine the number of resonant response peaks in a predetermined frequency interval. The distribution of the resonance frequencies is then characterized in a manner effective to form a unique signature of the object. In one characterization, a small frequency interval is defined and stepped though the spectrum frequency range. Subsequent objects are similarly characterized where the characterizations serve as signatures effective to distinguish objects that differ from the reference object by more than the predetermined tolerance.

This multi-contributed volume provides a practical, applications-focused introduction to nonlinear acoustical techniques for nondestructive evaluation. Compared to linear techniques, nonlinear acoustical/ultrasonic techniques are much more sensitive to micro-cracks and other types of small distributed damages. Most materials and structures exhibit nonlinear behavior due to the formation of dislocation and micro-cracks from fatigue or other types of repetitive loadings well before detectable macro-cracks are formed. Nondestructive evaluation (NDE) tools that have been developed based on nonlinear acoustical techniques are capable of providing early warnings about the possibility of structural failure before detectable macro-cracks are formed. This book presents the full range of nonlinear acoustical techniques used today for NDE. The expert chapters cover both theoretical and experimental aspects, but always with an eye towards applications. Unlike other titles currently available, which treat nonlinearity as a physics problem and focus on different analytical derivations, the present volume emphasizes NDE applications over detailed analytical derivations. The introductory chapter presents the fundamentals in a manner accessible to anyone with an undergraduate degree in Engineering or Physics and equips the reader with all of the necessary background to understand the remaining chapters. This self-contained volume will be a valuable reference to graduate students through practising researchers in Engineering, Materials Science, and Physics. Represents the first book on nonlinear acoustical techniques for NDE applications Emphasizes applications of nonlinear acoustical techniques Presents the fundamental physics and mathematics behind nonlinear acoustical phenomenon in a simple, easily understood manner Covers a variety of popular NDE techniques based on nonlinear acoustics in a single volume