LCR波切向应力检测系统的声时测量研究

该文提出了一种基于声弹性理论,利用临界折射纵波(LCR)从表面测量零件内部切向应力的实验方案,并依据固体中超声波传播特性与零件内部应力状态的关系,搭建了基于传播声时的切向应力测量系统。系统中临界折射纵波在被测零件内传播声时的测量采用"过零检测"方式,以减小由不同电子器件间性能差异所造成的测量误差,并利用时间-数字转换芯片实现高精度的时间间隔测量,从而提高整个系统的测量准确性。

Study of Travel-Time Measurement in Evaluating the Longitudinal Stress Using LCR Wave

An experimental method for measuring the stress of accessory is presented in this paper. Based on the acoustoelastic theory, this method can measure the stress from the surface of accessory using critically refracted longitudinal (LCR) wave. According to the relationship between the ultrasonic propagation characteristic and stress condition, a measurement system based on the travel-time is constructed. The "zero-crossing" method is adopted in measuring the travel-time to reduce the errors coursed by character differences of the electronic components. The travel-time of LCR wave is measured by time go digital converter(TDC) with high accuracy.