Some remarks on propagation characteristics of ridge guides for acoustic surface waves at low frequencies

Abstract

The plane-stress equations of the theory of elasticity are solved to predict the propagation characteristics of flexural and pseudo-Rayleigh modes of infinitely tall ridge guides for frequencies lower than the lowest thickness-shear frequency of thin plates. The parabolic dispersion characteristic of the former mode shows appreciable departure from the hitherto published results in the above limiting case. The large discrepancy is due to the incompatibility of the flexural type of motion in the ridge and the only Rayleigh type of disturbance that the adjoining free substrate can sustain. This causes undesirable radiation of the surface wave energy into the bulk of the substrate and is responsible for cutoff frequencies obtained by several authors. The consequent implication for the useful operational range of such waveguides is discussed. The nondispersive velocity of the latter mode at dc is found to be 1.5% lower than a microwave network result.

Effect of the stiffness and inertia of a rib reinforcement on localized bending waves in semi-infinite strips

“…In the West, the first publications on the subject were authored by Sinha (1974) and Thurston and McKenna (1974), that rediscovered the same phenomenon concurrently and independently, without being aware of Konenkov's contribution. Such a solution has also been represented recently by Kauffmann (1998).…”

Edge waves in asymmetrically laminated plates

“…The existence of edge waves was demonstrated by Konenkov (1960), Thurston and McKenna (1974), Sinha (1974), Lagasse and Oliner (1976), and Kauffmann (1998) for isotropic plates and by Norris (1994) for orthotropic plates, all using the classical theory of thin plates. Norris et al (2000) where u 1 and u 2 are the in-plane displacement components at the mid-plane, wðx 1 ; x 2 ; tÞ is the deflection of the mid-plane, and y 1 ; y 2 are related to w through y 1 ¼ Àw ;1 ; y 2 ¼ Àw ;2 .…”

Flexural edge waves and Comments on “A new bending wave solution for the classical plate equation” [J. Acoust. Soc. Am. 104, 2220–2222 (1998)]

“…The wave has properties analogous to a Rayleigh wave on an elastic half-space, in that it decays exponentially with distance from the edge. This result was apparently not very widely known in Western scientific circles, not an uncommon situation in the 1960's and 1970's, because it was rediscovered concurrently and independently by Sinha 2 and by Thurston and McKenna, 3 both published in 1974 in ''western'' journals. The first author of this Letter was likewise ignorant of Konenkov's original contribution when he proved that the edge wave also exists on anisotropic plates.…”