A review of welding residual stress test methods

Due to local uneven heating during the welding process, the residual stress of the structure after welding affects the reliability of it. In order to ensure the reliability, it is of great significance to test the residual stress distribution of the welded joint. It has always been the focus to find a simple and feasible method for residual stress testing to quickly and accurately obtain the residual stress distribution of welded joints. The mechanical measurement method has high measurement accuracy, convenient and easy operation, but it will cause certain damage to the components. Physical measurement method can avoid damage to components, but its test cost is usually high, and its measurement accuracy can also be affected by the material microstructure characteristics of welded components. Based on the advantages and disadvantages of these two residual stress test methods, a modal test method is proposed. This method is a non-destructive measurement method. Based on the mathematical relationship between the residual stress of the welded structure and the natural frequency (mathematical model), the natural frequency is measured through the modal test to calculate the residual stress quickly. However, it is difficult to establish a mathematical model with this method, and it is not suitable for realization.