超声换能器辐射场应力定量测量方法研究

Research on quantitative stress measurement method of wave field radiated from an ultrasonic transducer

提出了一种基于动态光弹观测系统的超声换能器在透明固体中辐射场应力定量测量新方法。该方法关注到激光束穿过非均匀应力区时的双折射累积效应和Senarmont补偿法均匀应力假设与真实应力非均匀分布之间的差异,利用滤波反投影算法重建出应力场;根据应力与换能器激励电压的线性关系,用4种激励电压动态校准重建后的应力数据。实验定量测量了圆形晶片超声换能器在固体内部辐射的瞬态纵波场的应力分布,结果表明应力幅值与激励电压成正比,符合线性规律。

A novel method is proposed for the quantitative stress measurement of wave field in transparent solid radiated from an ultrasonic transducer.Filtered Back Projection algorithm is used to reconstruct the stress field taking account of the accumulation of the birefringence effect from a laser beam and the difference between inhomogeneity of real stress field and homogeneity assumption of observed stress with Senarmont compensation method based on a dynamic photo-elastic measurement system.The reconstructed stress data is dynamically calibrated with 4 different electrical excitatory voltages to ultrasonic transducer according to linear function of stress amplitude against excitatory voltage.The measurement of radial stress field of longitudinal transient wave from a circular wafer transducer is experimentally made,which verifies that the stress amplitude is proportional to the excitatory voltage with agreement to linear function.