超声压电换能器中的机械预应力。

The mechanical pre-stressing in ultrasonic piezotransducers.

作者信息

Arnold F J, Mühlen S S

机构信息

Superior Center of Technology Education, Campinas State University, Limeira, SP, Brazil.

出版信息

Ultrasonics. 2001 Jan;39(1):7-11. doi: 10.1016/s0041-624x(00)00048-2.

DOI:10.1016/s0041-624x(00)00048-2

PMID:11205588

Abstract

Composed piezotransducers submitted to mechanical pre-stressing present shifts on resonance and anti-resonance frequencies. Changes on characteristic parameters of the ceramic and in the coupling between the parts of the transducer can be the causes for this behavior. In applications where the level of pre-stressing is low (up to 50 MPa) the parameters of the ceramic are not altered, therefore, the shifting on frequencies are attributed to coupling between parts. This paper describes a mathematical model to explain this effect based on difference of effective cross-section between transducers parts under pre-stressing. The results show a proportional relation between pre-stressing and effective coupling of the parts.

摘要

施加机械预应力的复合压电换能器在共振和反共振频率上会出现偏移。陶瓷特性参数的变化以及换能器各部分之间耦合的变化可能是导致这种现象的原因。在预应力水平较低（高达50兆帕）的应用中，陶瓷的参数不会改变，因此，频率偏移归因于各部分之间的耦合。本文描述了一个数学模型，以基于预应力作用下换能器各部分有效横截面的差异来解释这种效应。结果表明，预应力与各部分的有效耦合之间存在比例关系。