扭转振动压电超声换能器的研究

用声强技术检测区分板壳结构的空气传声与结构传声时，结构的辐射效率之差决定了检测结果的可信度，文中分析了实际结构的在声场激励下的实测辐射效率与无限大结构的空气传声辐射效率之差，及对区检测结果的影响。实验结果证实了理论分析。

Study on the piezoelectric torsional transducer

In this paper, I studied the composite torsional transducer which consists of the piezoelectric ceramic pile of circular pipes, the front and the back metal cylinders.First the torsional vibration of the tangentially polarized piezoelectric ceramic slender pipe is analyzed, the electromechanical equivalent circuit is derived and the concept of the cross sectional torsional coefficient is proposed. Then, based on the equivalent circuit, the torsional vibration of the tangentially polarized piezoelectric ceramic pile is studied by means of the network theory and the equivalent torsional soun speed in the pile is obtained. At last the resonance frequency equation of the composite torsional transducer is derived, which can be used to design the torsional transducer for different applications.