The Study And Applications Of T-Component Welding Inherent Strain

Welding is one of the most methods in steel structure connection and widely used in industries to assemble various products including ships, automobiles and bridges. Welding distortion often results in problems such as dimensional and deformation inaccuracies during the assembly and increased fabrication costs. Therefore, prediction and reduction of welding distortion are critical to improve the quality of welded structures and have significant theoretical and practical application value.The paper adoped the inherent strain theory studied the prediction of the deformation of the large welded structure. Numerical simulation is applied to studied the welding distortion of the T type joint which is widely used in practical application. Firstly, thermal elastic-plastic finite element method is employed to estimate the welding distortion of the T type joint with ANSYS and the temperature, residual and stress fields are obtained. Based on the results of the numerical simulation, the calculation methods of the inherent strain is anslyzed. Through changing the size of the dimensional of the T type joint, the transverse inherent shrinkage distribution, the longitudinal shrinkage distribution and the angular distribution are anslyzed. Therefore, the finite element dimensional of the T type joint is identified. Secondly, based on the thermal elastic-plastic FEM, the distribution of inherent strain under the action of a single factor which includes the weld velocity, the fillet length and the thickness of the flange is studied. Numerical simulation results indicate that the heat input and the thickness of the flange are the most important affecting factors. Through the analysis of numerical simulation results from different thicknesses of the flange and the heat input under the best standard welding condition, the inherent strain is obtained. Finally, the inherent strain law is applied to the cabin floor structure and the welding distortion of the cabin floor structure is predicted. According to the value and the trend of the distortion, the control of the distortion methods is studied.