光弹法测量超声换能器声场

Photoelastic quantification of ultrasonic beams radiated by transducers

超声换能器声场的测试对于超声检测具有基础性作用,而传统的超声换能器声场测试方法具有一些局限性。本文介绍了搭建的动态激光光弹实验平台,并利用动态光弹法测量了纵波换能器和横波换能器辐射声场的特征,由瞬态声场图像获得了传声介质的声波速度及超声换能器的中心频率;由稳态声场图像获得了声场的近场长度、指向性和扩散角等参数;分析了光弹实验系统和测量方法可能引起测量误差。本文结果表明动态光弹法是一种有效的定量测量超声换能器声场的方法。

It plays a fundamental role to quantify the ultrasonic beams radiated by transducers for ultrasonic testing. However, traditional methods have some limitations. A photoelastic visualization system was established and utilized to quantify some parameters of ultrasonic beams radiated by a longitudinal transducer as well as a shear one. Wave velocities and central frequencies of the transducers were obtained by transient ultrasonic fields. The near-field distances, directivities and divergence angles were calculated from time-harmonic ultrasonic field. The measurement errors caused by the photoelastic visualization system and experimental method were analyzed. It shows that the photoelastic technique is an effective method to quantify ultrasonic beams radiated by transducers.