Numerical Analysis And Experimental Measurement Of Residual Stress On Steel Structures

Welding is one of the most common used connections of steel structure. Welding process is localized heating, and then cooling, non-uniform temperature change near the weld will cause residual stress and deformation. The existence of welding residual stress and deformation will affect the precision of machining and installation of steel member and reduce the carrying capacity and stability of the steel member, especially have significant adverse effects on the fatigue properties of steel member. In this paper residual stresses on steel member are determined by blind-hole method and numerical analysis, and the comparison of the results between them is made. And it makes finite element calibration of strain relief coefficient of blind-hole method with consideration of plasticity and off-center of the hole.The main contents of the paper are showed as follows:(1) This paper introduces the basic theory and method of the measurement of welding residual stress when using blind-hole method, and the methods of numerical simulation of welding residual stress. In addition, the key technologies in simulation of welding process using ABAQUS are discussed in this paper.(2) This paper introduces the finite element calibration of strain release coefficient, and makes finite element calibration of strain relief coefficient with consideration of off-center of the hole or not. General equation of strain release coefficient considering the off-center of the hole is obtained.(3) Residual stresses on butt welding steel plates are determined by blind-hole method and numerical analysis, and the comparison of the results between them is made.(4) Residual stresses on butt welding steel pipes are determined by blind-hole method and numerical analysis, and the comparison of the results between them is made.The results of the numerical analysis and experiment measurement were compared. It proves that using the strain release coefficient of finite element calibration with consideration of off-center of the hole can effectively reduce the error of residual stress measurement by blind-hole method caused by eccentricity of the hole drilling. The applicability of numerical analysis in welding residual stress determination for steel structures was verified. It was also found that the size effect of the weld should be considered in numerical analysis to assure more accurate assessment of actual welding residual stresses.