The influence of electrical boundary conditions on the occurrence of anomalous resisto-acoustic effect

As known, anomalous resisto-acoustic effect is a fundamental property for weakly inhomogeneous piezoactive waves (Bleustein - Gulyaev, Love, and some leaky waves). It consists in that the velocity of aforementioned waves first increases, achieves its maximum, and only then decreases with growing conductance of a layer placed at the surface of piezoelectric half-space. In this paper we continue to study the peculiarities of the effect occurence and the influence of different electrical boundary conditions on its characteristics. Conditions have been found under which the said effect occurs and, respectively, dissappears. The magnitude of positive change in velocity with growing layer conductance is demonstrated to be reduced up to zero as a layer with arbitrary conductance has been removed from the piezoelectric surface. The positive change in velocity is, respectively, increased with removing an perfectly conducting screen from the “piezoelectric half-space – conducting layer” structure. As piezoelectric the potassium niobate has been used. The obtained results are useful for a more deep understanding the physical bases of propagation of weakly inhomogeneous piezoactive acoustic waves.