APPLIED ACOUSTICS, vol.37, no.3, pp.199-212, 1992 (SCI-Expanded)
In this study, a general approximate theory which has been proposed for the dynamic behavior of viscoelastic plates and layered composites is assessed by considering the propagation of out-of-plane shear waves in an elastic layer. This somewhat simple problem was chosen for assessment because the solution using the exact theory can be obtained numerically with good accuracy. The approximate equations of the problem are integrated by employing the method of characteristics whereas the exact equations are solved by a transform technique together with the method of characteristics. From a comparison of the approximate and exact results, it is found that the approximate theory can predict very well the transient waves propagating in a layer and their geometric dispersions due to reflections at the boundaries, and that it is capable of describing the sharp variations at wave fronts.