基于光栅扫描焊接残余应力轮廓法测量技术研究

Research on contour method measurement technology of welding residual stress based on grating scanning

目前测量焊接残余应力的轮廓法都是采用三坐标机对被测件切割面轮廓进行测量,但三坐标机的测量过程是逐点测量,测量效率低、测点少,该文针对这一问题,提出一种基于高精度光栅扫描测量切割面轮廓的轮廓法。以Q235板材为被测对象,对其焊接残余应力进行测量。首先,采用高精度光栅扫描仪对Q235板材切割面轮廓进行测量;其次,从测量得到的海量点云中提取了轮廓节点数据;再次,进行应力重构,得到板材在该截面处的法向残余应力云图;最后,将得到的测量结果与基于三坐标机测量的轮廓法测量结果进行对比,偏差在50 MPa以内,论证该文方法有效。实验结果表明:该方法具有测量精度高、速度快、测点多的优点,能够满足焊接残余应力测量的需求。

At present, the contour method of measuring welding residual stress is to measure the contour of the cutting surface by CMM, but the measurement process of CMM is point by point measurement, therefore, the measurement efficiency is low and the measurement points are few. In order to solve this problem, a method of measuring the cutting surface contour based on high-precision grating scanning is proposed. In this paper, the welding residual stress of Q235 plate is measured. Firstly, the cutting surface contour of Q235 plate is measured by this method. Secondly, the contour node data is extracted from the measured massive point cloud.Thirdly, the normal residual stress nephogram of the plate at the section is calculated. Finally, the experimental results obtained by this method are compared with the experimental data of contour method based on CMM to verify the accuracy of the method of this paper. The deviation is less than 50 MPa. The experimental results show that the method has the advantages of high precision, high efficiency and large amount of measurement data, and can meet the requirements of welding residual stress measurement.