中文摘要：

设计了一种锥变截面管形超声振动系统，振动系统由夹心式压电换能器和锥形变截面金属圆管组成。推导了锥变截面管形超声振动系统的等效电路和谐振／反谐振频率方程。利用等效电路法、有限元法对锥变截面管形超声振动系统进行了分析设计并制作了相应的实验样品。研究结果表明，锥形变截面管的等效电路为一种新型的非互易二端口等效网络；锥变截面管形超声振动系统具有较好的频率隔离性、较大的位移振幅和均匀的振动位移输出。该超声振动系统可望在超声连续缝焊、环形部件的超声切割和超声钻孔等领域获得应用。

英文摘要：

A tubular ultrasonic vibrational system with a conical varying cross-sectional area is designed. It is composed of a sandwich piezoelectric transducer and of a tubular ultrasonic resonator with the conical varying cross-sectional area. The equivalent circuit of the tubular ultrasonic vibrational system is deduced and the resonance/anti-resonance frequency equations are obtained. The vibrational system is analyzed and designed by the equivalent circuit method and the finite element method, an experimental prototype is also manufactured. The results show that the equivalent circuit of the tubular ultrasonic resonator is a novel non-reciprocal two-port equivalent network, and the tubular ultrasonic vibrational system has a good vibrational performance： better isolation of the operating frequency from close non-tuned modes, uniformity of amplitude at the working surface and high amplitude of the operating mode. It is expected to be used in some ultrasonic applications, such as continuous seam welding of plastic sheet or strips, ultrasonic cutting of a ring-type plastic element and ultrasonic drilling, etc.