Interaction of flexural waves with a moving line of a ball-and-socket attachment of a thin plate

The interaction of plane monochromatic flexural waves with a uniformly movi ng line of a ball-and-socket attachment of a thin plate is considered. It i s demonstrated that, in a limited interval of the angles of incidence, and in the case of the line of attachment moving away from the source, a specia l case of reflectionless birefringence is possible along with the reflectio n of flexural waves. For reflectionless birefringence, the presence of a po le of the amplitude coefficients at the upper boundary of the interval of i ncidence angles is revealed. The origin of reflectionless birefringence is attributed to the appearance of a new type of natural waves caught (capture d) by the moving inhomogeneity. The unrestricted behavior of the amplitude coefficients of waves approaching the pole is interpreted as a manifestatio n of the spatial resonance of the incident wave with the wave caught by the line of attachment.