Numerical Simulation Of Temperature And Stress Field In Welding Trailing Based On The Finite Element

Welding is a complicated physicochemical process which involves in electromagnetism, heat transferring, metal melting and freezing, phase-change welding stress and deformation and so on. However, the overwhelming majority welding process all can engender complex welding residual stress, crack, blowhole and so on in the work part, which reduce the welding structure performance, and affect the welding quality.Hammer peening is a kind of very effective method relieving welding residual stress, which was applied widely in engineering. However, the research of hammer peening can far meet its applications in practice. If welding process can be simulated with computer, obtained welding temperature field and stress field at different times, then can offer position and occasion of hammer peening for the weld with trailing peening.Based on summing up other's research, employing numerical calculation method, discussed the finite element analytical system of the welding process, expound the numerical simulation method and basic theory of temperature field and stress field in welding process. When calculating, use ANSYS' thermal-structure couple function, firstly calculate welding temperature field and save the result if it is right, then using the temperature result as load to calculate welding stress field. Although welding temperature filed and stress, strain field are bi-directional couple, but stress and strain field have little influence on temperature field, this paper only considers the single couple which temperature field effects on stress and strain field. Then provide the simulation method of welding temperature field and stress field of flat surface by FEM soft ANSYS. At the same time, the calculation result accord with traditional analysis result and theory result.The main contents of the paper are as following: choose the function of Gauss as heat source model, use APDL of ANSYS software to apply load of moving heat source. A mathematical model of transient thermal process in welding is established to simulate the move of heat source. The problem of the fusion and solidification of material has been solved by the method of changing the element attribute. Simulated single track bead weld of submerged arc welding, ignored metal deposition of weld bead, and solved the problem of the convergence difficulty or the un-convergence during the calculation of the thermal stress.A feasible dynamic simulation method on 3D welding temperature field, stress field has been established, which provides theory foundation and instruction on optimizing the welding technology and parameters, and provides theory foundation for the weld trailing peening technology at the same time.