摘要
以LFMCW(linear frequency modulated continuous wave)时间间隔测量原理为基础,针对LCR波(the critically refracted longitudinal wave)声弹性应力检测脉冲激发方式时存在的问题,提出了一种基于LFMCW方式激发LCR波的切向正应力检测系统,使用新的检测方法通过发射信号和接收信号形成的拍频信号来反映波的传播时间,用抛物线插值与最小二乘相结合的数字测频方法准确测量拍频频率。实验结果证明了该系统对LCR波传播声时检测的有效性。
The pulse ultrasonic exciting approach based on the sonic elastic theory to measure the stress with the critically refracted longitudinal wave（LcR wave） was inefficient. Through research on the principle of time-interval measurement with linear frequency modulated continuous wave, an optimized test system with LFMCW method to stimulate the LCR wave is introduced. The beat frequency signal produced from the waveform transformation in the propagation process can reflect the travel time with emission signals and received signals, and in contrary to the former study, they can accurately measure the frequency with a frequency measurement algorithm using parabola interpolation and least square method. The experimental results show the effectiveness of the new approach in the detection of propagation time with LCR wave.
出处
《电子测量与仪器学报》
CSCD
2009年第11期72-78,共7页
Journal of Electronic Measurement and Instrumentation
基金
电子科技大学中青年学术带头人培养计划(编号:Y02018023601015)资助项目
