超声法焊缝残余应力检测技术研究

文中基于声弹性理论,研究临界折射纵波(Critically Refracted Longitudinal wave,LCR wave)残余应力检测原理,通过超声波传播速度的变化,反映出构件表面和内部的残余应力,从而验证采用LCR波检测构件中残余应力的关键技术,具体包括LCR波的激发、接收和后续处理。设计并制作了基于声时的残余应力检测实验系统。声时是整个测量系统中的关键量,其测量水平决定残余应力的测量精度。在实现过程中采用"一发一收"的探头布局模式,通过测量固定长度上声时传播的变化,分析残余应力的分布情况。

Residual Stress Measurement for Welded Structure by Ultrasonic Wave

In this paper,we proposed a method of residual stress measurement for welded structure using Critically Refracted Longitudinal(LCR) wave based on acoustic elastic theory.Acoustic time can reflect the residual stress existing on the surface and interior of the components,the key techniques of residual stress detection by LCR wave can be demonstrated.These techniques include LCR wave incitation,receiving and signal processing.The residual stress measurement system is designed and implemented in this paper.Acoustic time is a key value for the measurement system,the precision of the residual stress measurement depends on the key value.System implementation adopts the mode of "one sending and one receiving",the residual stress is analyzed and evaluated through measuring the change of acoustic time on fixed-length.