Comparison of D15 and D35 Wafers to Excite the Fundamental Shear Horizontal Wave

摘要

The accuracy and reliability of on-line monitoring system of pressure vessels are normally affected by high pressure fluid mediums inside. Therefore, an effective method to deal with this problem has recently been introduced by using single mode waves, such as the fundamental shear horizontal wave (shorten for SH0 wave) for its non-dispersive characteristics and no out-of-plane particle displacement. In order to excite single SH0 wave by wafers, all shear modes of the commercial piezoelectric wafers that can generate shear horizontal waves are reviewed firstly. Next, the wave directivity and strength actuated and sensed by the d15 and d35 wafers with different geometric dimensions are compared by finite element simulations. Results show that the waves excited by different wafers depend on the geometric dimensions and shear modes of the wafers. Moreover, the rectangular d35 mode piezoelectric wafers are investigated as the preferred ones to actuate and sense the SH0 wave. Finally, an experiment system is setup and it is validated that the d35 mode wafers can successfully excite and sense the single SH0 wave. This work can greatly promote the application of SH0 wave in the on-line long-termly monitoring of pressure vessels.