ABSTRACT
This chapter summarizes the 1D results and write them in the notation for longitudinal and transverse waves in solids. This is followed by the 3D theory for isotropic solids. The chapter describes the propagation properties of ultrasonic waves and attenuation mechanisms in a number of important cases. Elasticity theory provides a complete description of the static properties of a mechanical system, and in fact parameters such as the elastic moduli can also be used to describe the dynamic properties over the full ultrasonic frequency range. The energy and acoustic power relations for both longitudinal and transverse waves can be extended directly from their 1D forms. A viscoelastic solid is an intermediate case between solids and liquids.
