超声波法曲面工件残余应力测量

Curved convex face residual stress measurement by ultrasonic method

开发了超声波法焊接残余应力测量系统.用该系统配合平直探头对曲面工件的焊接残余应力进行测量尝试.将超声波法获得的测量结果与激光全息小孔法的测量结果比较,超声波法测量所得的焊接残余拉压应力区间与小孔法相同,分布曲线较小孔法测量结果缓和,最大拉压应力均要小于曲面工件中实际拉压应力.根据试验结果,结合名义声弹性常数表达式分析了曲面耦合状态对超声波法测量结果的影响.提出用超声波法测量曲面工件需要根据工件曲率半径修正声弹性常数,减小曲率半径导致的耦合误差,提高测量结果的准确性.

An ultrasonic residual stress measurement system was developed to detect residual stress on curved convex face with one-emit-one-receive transducer.Compared with the results of laser holography orifice method,the distribute section of tensile stress and compression stress are similar,both max tensile and compression stress of ultrasonic method are much lower than that of laser holography orifice method,and stress distribution line is more gently as well.According to the couple condition of transducer and analysis of the nominal acoustic coefficient,the results of ultrasonic residual stress measurement on curved convex face should be corrected with radius of curvature in order to get precision residual stress.