Releasing Welding Stress Of Cylinder Vessel With Mechanical Vibration Combining Multi-Order Modal And Excitation Points

Although VSR(vibration stress relief) has been used for many years, but it could only release 10%～15% of stress, which can not satisfy the quality requirments of industrial manufacture. Because the study about how to use technology of VSR has not gone deep and integrally. This mainly appears in three aspects specifically. The first is that excitation frequency which is regarded as one of the key technological parameters of VSR is low. The second is that excitation frequency is not selected based on modal analysis rationally. The third is that there are no studies about how the number of excitation point influence effect of VSR. The result of this is that the use of VSR technology is not widely.To solve this problem, a new way of VSR with more excitation points based on modal analysis is proposed, which is called VSRPM for short. This method needs to select excitation frequency and the number of excitation point on the basis of modal analysis. And the selection of other technological parameters of VSR is in accordance with traditional methods. We have used welding strucuture of cylinder vessel of thin wall to testify the proposed method, and studied if VSRPM could make crystalline grain more small and perfect. In the experiment, the method of blind hole is used to measure welding residual stress. To prove the effect of VSRPM experiment completely, three other experimental teams were needed as contrast. We also used ANSYS to simulate the process of VSRPM.The results of experiment and simulation all prove that the effect of VSRPM has been improved in large measure. The entire welding residual stress has been released in large degree and the phenomemon of stress concentration is eliminated. The whole field of stress become more balanced.