The field and radiation impedance of mechanical radiators on the free surface of a semi-infinite isotropic solid

Abstract

Definite integral representations are obtained for the field at an arbitrary point in a semiinfinite solid, due to stresses on the free surface which vary sinusoidally with time. From these integrals, asymptotic expressions have been obtained for the field at infinity in the solid, and polar diagrams showing the variation of field strength with direction are given. Integrals are also found for the mean displacement over the externally stressed region of the surface, and these have been evaluated numerically in a number of cases to obtain the radiation impedance of the sources represented by such stress systems.