Study Of The Measurement About The Residual Stress In Thickness Plate Weldment

The study of residual stress occupies a very important position in the field of the weldment research. On the research about the welding technology, we usually take those numbers that tested by blind hole drilling method as the standard of the change's effectiveness. In the numerical simulation of the welding process, we also compare the result with the result that comes from the residual stress measurement method. When we try to understand the distribution of residual stress in different materials and different welding types, it's necessary for us to take some residual stress test. At present, there are many ways to test the residual stress. But we still cannot ensure the distribution of the residual stress. This situation is mainly caused by the lack of the intersectional study. Especially, we need the study of changing the testing approach by the intersectional study. As our awareness to the research of the approach of the testing residual stress is not very clear, our study to the distribution of the residual stress is limited. For the same reason, when we use the finite element software to simulate the welding process, facing a lot of numerical results we cannot judge which kind of simulation method is more similar to the actual distribution of the residual stress.Based on this situation, in this thesis, I have chosen the X-ray measurement method and blind hole drilling method to test some points residual stress in heavy plate weldment, and compared the two way's results.In this paper, I have done some experiment about the X-ray measurement's pre-operation. And then, I have tested residual stress in heavy plate weldment in the section that perpendicular to the weld direction with the X-ray measurement method and blind hole drilling method. At last, I have test the residual stress that before and after testing by the blind hole drilling method. Then I made a contrast by these two tests.According to test the residual stress of the surface that after sanding, we found that the surface after sanding does not conform to the diffraction rule. From the Angle of X-ray measurement method, we understood that there is something wrong with sanding surface. Then I proposed some suggestion to the blind hole drilling.According to the X-ray measurement and the blind hole drilling methods'result showed that the two kind of testing's result is similar. But in some points the number shows some different.After contrasting the residual stress before and after drilling a hole, we found that at the hole nearby area that the radius is between 10mm-70mm, the residual stress has declined by 30MPa. After testing the 3 section's residual stress, we found that there are some sections'distribution of residual stress that do not accord with the symmetrical double peak curve. In these sections the distribution of residual stress was found to be distorted. By testing the residual stress in the area of toe of weld, we can find these distort sections. But whether this kind of way of finding out the distorting section is effective or not, we still need further research.