BROADBAND DISPERSION BEHAVIORS OF WEDGE WAVES PROPAGATING ALONG LARGE-ANGLED WEDGES

摘要

Broadband dispersion behaviors of wedge waves traveling along large-angled wedges are investigated with a laser ultrasound technique. Wedge waves are guided acoustic waves propagating along wedge tips. Until now, no elasticity-based close-form solution is available for the prediction of dispersion behavior of wedge waves. By assuming the wedge as a thin plate with variable thickness, McKenna obtained a theoretical approximation for the prediction of dispersion relation of truncated wedges within limited apex angle and bandwidth. The current research provides experimental data on wideband dispersion spectra of wedge waves traveling along large-angled wedges. It is found that the thin plate theory is accurate only within a small wavenumber regime. Also, a limiting behavior in the large wavenumber regime the ASF dispersion spectra are found to approach the Rayleigh wave speed.