Stress Concentration And Fatigue Life Research Of Steel-Pipe-Welded Hollow Spherical Joints

With the rapid development of economy, grid structure has been widely applied, While the fatigue problem of grid are also increasingly prominent, has aroused the domestic and foreign academic and engineering circles. Research shows that the fatigue of grid structure is mainly fatigue of welded hollow spherical joints, so the research of grid node fatigue problem is of great significance. Fatigue is the key to life estimation of component, in order to better grasp the structure performance, ease of use. At present, the fatigue test is the most effective method of fatigue research recognized. Based on the National Natural Science Foundation of grid structure joints fatigue test as background, the following study on the basis of fatigue data,1. According to the analysis of stress concentration of Steel-Pipe-Welded hollow spherical joints, compared with the static test data, the results are consistent to the theoretical and test, and get the stress concentration factor.2. Analysis of the influence factors of fatigue and fatigue failure mechanism.3. Using the cumulative damage theory, Miner rule and Paris formula based on fracture mechanics of fatigue life is estimated based on the ball joint.Through this research, provided some experimental and theoretical basis for the fatigue life estimation of component.