基于全包络权重算法的超声波法残余应力无损测量系统

Ultrasonic residual stress measurement system based on entire envelope weighting algorithm

关键词:  超声波法  焊接残余应力  全包络权重法

Key words:  ultrasonic  welding residual stress  entire envelope weighting algorithm

摘要:

超声波法残余应力测量基于声弹性效应,针对超声波法测量精度的若干影响因素,为更精确的测量焊接残余应力,提出全包络权重算法,同时考察应力梯度引起的超声信号包络不同位置参考点信号差. 用虚拟仪器软件实现,使超声波法焊接残余应力测量误差大大减小,实现了焊接残余应力超声波法的高精度测量. 使用不确定度对开发的高精度超声波法测量系统的测量精度进行了表征及评价,焊接残余应力场多次重复测量试验结果表明,基于全包络权重算法的高精度超声波法残余应力测量系统不确定度大大减小,焊接残余应力测量结果更为精确稳定.

Abstract:

Traditional stress measurement methods are time-consuming and destructive. Ultrasonic stress measurement method was used to overcome these disadvantages based on the acoustoelasticity theory. Ultrasonic stress measurement experimental equipment was established with Lcr waves. This method has proved its accuracy and reliability by actual measurement of such industrial structures as electric multiple units(EMU) and rockets. The entire envelope weighting algorithm was proposed to reduce the influencing factors for measurement accuracy, by which uncertainty of the system is lower than threshold method.