Measurement of the Acoustic Properties of Solid Polymers,
NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD
Pagination or Media Count:
The speed and attenuation of an acoustic wave in a homogeneous polymer can be measured directly in the laboratory at frequencies greater than 100 kilohertz. At lower frequencies, however, it is usually necessary to calculate the propagation properties from measurements of the dynamic elastic moduli and the density. Data on two of the three standard moduli bulk, Young, and shear are theoretically sufficient to describe any type of acoustic propagation in a homogeneous material. Each modulus consists of a storage modulus, indicating the in-phase component of stress and strain, and a loss modulus, indicating the out-of-phase component. A wide variety of measurements techniques has been employed, depending on the type of modulus to be studied and on the frequency range of interest. A survey is presented of the commonly used techniques, and their relative advantages and limitations are discussed.
- Solid State Physics