Use of reciprocity theorem for computation of low-frequency radiation patterns

Starting with a simple word statement of the reciprocity which exists between forces and displacements in a general elastic solid, it is shown that low-frequency radiation of shear and compressional waves from relatively complex sources can be obtained by solving relatively simple problems in static elasticity. Illustrative examples include radiation from radial and tangential pairs of forces acting on the wall of a cylinder, pressure in a finite cylinder, and a pair of radial forces in a hole in a plate. For the last case, measurements in a plexiglas plate compare favorably with computations.