Numerical Simulation of Welding Temperature Field and Stress Field of Offshore High-Strength Steel

Abstract Objectives/Scope With the extensive development of offshore installations, an increasing number of offshore structures are constructed using high-strength steel. The high-strength steel is susceptible to welding residual stress. And it is cost-prohibitive to rely solely on welding experiments. Therefore, utilizing numerical simulation technology to investigate the welding process of offshore high-strength steel holds significant scientific research value. The research aims to study the influence of process parameters on welding temperature field, residual stress and deformation by the finite element method. Methods, Procedures, Process In this paper, a three-dimensional model of a V-groove welded joint of offshore high-strength steel was established using Ansys software. And the welding process was simulated with a volume heat generation heat source. The bidirectional coupling between the temperature field and stress field during plate butt welding was analyzed using a direct method. The influence of welding current on the temperature field and stress field in high-strength steel butt welding was investigated while keeping the welding voltage and speed constant. Results, Observations, Conclusions Firstly, the distribution of temperature fields in the weld and base metal was analyzed. The temperature in and around the molten pool was the highest, and the heat was gradually transferred outward. The increase of welding current directly resulted in an increase of welding heat input, leading to a higher peak temperature field. Furthermore, the evolution of residual stress distribution under different welding currents was examined. The peak residual stress increased with temperature, particularly the residual compressive stress at the weld position, causing the changes of the stress state along the weld center line in the X and Y directions. The deformation and displacement of welded joints were obvious in macroscopic view. Novel/Additive Information The mechanism of welding is complicated, and its application in the offshore high-strength steel has great prospects. The simulation results can provide some theoretical guidance for the optimization of welding process parameters of offshore high-strength steel, which has great practical significance and economic value for improving the quality of welded joints.