Abstract
Using the rotating plate method in which ultrasonic transmission is plotted as a function of the angle of incidence, velocities and attenuations of the waves in viscoelastic solids are experimentally obtained. The theory of ultrasonic transmission through a plate made of viscoelastic material in the preceding paper is employed for the analyses of the experimental results obtained. Details of an apparatus for making such measurements are given. The ultrasonic velocities and attenuations of poly-methylmetacrylate, ebonite, poly-vinyl-chloride and rubber have been measured with this equipment and the values obtained are shown to be in agreement with previously published data. It is noted that the velocity of rotational waves obtained from the apparent critical angle for rotational waves is always larger than the actual value on account of the absorptive property of the solid medium, and that for obtaining the exact value of the velocity the correct transmission curve and troublesome calculations are required.
