Numerical Simulation Of Welding Temperature Field And Stress And Strain Field Of T-Joint Based On The Sysweld

Welding is a multi-subject and complicated process which involves in arc physical,heat transferring,mechanics,metallurgy and material science and so on。Welding phenomena, which are produced in welding process including electromagnetism,heat transferring,metal melting and solidifying,phase change,welding stress and deformation have important influence on welding products or structures. If the controlling of welding process only depends on accumulated experience and process test, it need high cost and time-consuming. With the improvement of computer technology and the advances of the finite element calculation method, if once welding process can be simulated by computer, we will forecast the welding quality, control welding process, easily determine the optimum welding process methods and welding parameters, thus we can pointedly solve actual welding problem.T-joint is one of the most common welding joints, widely be used in vehicles, ships and marine engineering, aerospace engineering and other important welding structure, but compared with butt welding components, its the temperature field and stress strain field are much more complex, it also has no symmetry. The current study of numerical simulation of T-joint is relatively less, but in many cases T-joint welding quality requirement is very high, so in-depth research of the numerical simulation in T-joint becomes very necessary。This paper uses the finite element software SYSWELD to T-joint temperature field and stress strain field for 3d dynamic simulation, employs experiment, measures the welding residual stress and residual deformation. At the same time, it has the theoretical calculation to welding residual deformation, this paper mainly research work is as follows:1. The paper discusses systematically the finite element analysis theory of the welding process, introduces the SYSWELD software using method, and according to the actual welding characteristics of T-joint, it conducts the secondary development and checking for heat source model.2. Three-dimensional finite element analysis model is developed to simulate welding temperature field, stress and strain field. The contradiction between computing accuracy and computing speed is been taken into account. The meshing is close in the weld and surrounding area, on the contrary, thick away from the weld area. It chooses suitable time step and uses the method of "birth and death" method to filling out the simulation for weld metal.3. Based on the finite element software SYSWELD of T-joint welding temperature field for 3d dynamic simulation, the transient temperature field distribution as well as feature points thermal cycling curve is got, and through the finite element analysis, the relation of temperature which is located in any point of weld and phase transformation is obtained. Comparing the simulation results with the literature data, it is demonstrated that the established model of numerical simulation can preferably simulate the temperature field, which provides a foundation for analyzing stress, strain and decreasing the welding stress and deformation in welding process.4. Based on the finite element software SYSWELD of t-joint of the stress and strain fields for 3d dynamic simulation as well as applied double-ellipsoid heat source which is modified with the tool supplied by SYSWELD software, the equivalent stress distribution as well as the distributions of the longitudinal residual mean stress on the weld and transverse residual mean stress perpendicular to the weld is got, and through the finite element analysis, welding deformation cloud is obtained at different times. The welding longitudinally and transversely residual stresses of T-joint after welding, the distributive patterns of residual stresses matched basically well with the results of numerical simulation as well as testify the results of the numerical simulation. Meanwhile the test and theoretical calculation are proceeding on the welding residual strain, as well as match basically well with the results of numerical simulation and testify the results of the numerical simulation. Analysis results show that the established model of numerical simulation can preferably simulate the stress and strain field, which provides the great reference for decreasing the welding stress and deformation in welding process and inspecting and Optimizing welding process.