Prestress-induced dispersion-like effects on wave propagation in elastic compressible materials

The paper deals with wave propagation in an elastic homogeneous bar that includes a prestressed segment in it. The prestress in that segment may be due to some distortion forces acting upon the bar. The end surfaces of the segment act as discontinuity surfaces inside the medium. They partially reflect and partially transmit any pressure wave impinging on them. It is found that the coefficients of reflection and transmission are functions both of the prestress of the segment and of the frequency of the wave. This produces a prestress-induced dispersion-like phenomenon, which in principle should be capable of revealing the state of internal stress of the body.