超声检测用压电换能器瞬态特性可控可调

超声检测用压电换能器瞬态特性主要包括瞬态空间响应和瞬态时间响应。本文通过调整控制换能器和激励源,实现瞬态空间响应和瞬态时间响应的某些特性的可控可调。其中包括在空间响应方面消除边缘波以获得平行声束和消除平面波以获得聚焦绳声束;在时间响应方面,调整换能器的背衬阻抗以获得可调首次波幅比和调整换能器结构和激励电信号以获得任意检测信号等。

Controllability over the transient performances of piezoelectric transducers used in ultrasonic testing

The transient performances of piezoelectric transducers used in ultrasonic tes- ting mainly include transient spatial response and transient time response.This paper pres- ents the ways to control and adjust the transient performances through changing the trans- ducer structure and the exciting source.For the transient spatial response,it is possible to obtain a parallel acoustic beam by eliminating the edge wave,and a long axis focusing beam by eliminating the plane wave.For the transient time response,the first-second cycle amplitude ratio can be adjusted by changing the impedance of the transducer backing, while any arbitrary testing signal can be obtained by changing the transducer structure and the exciting signal.