Modeling of Thermomechanical Phenomena of Welding Process of Steel Pipe / Modelowanie Zjawisk Termomechanicznych Procesu Spawania Rury Stalowej

In this paper an analysis of phenomena of laser welding of steel thin-walled element is presented. Coupled mathematical and numerical models of thermal phenomena, mechanical and phase transitions in solid and liquid state are proposed. To the modeling of phase transformation in the solid state the macroscopic model based on the analysis of the CTP diagrams are used. In the simulation of thermal phenomena the solution of heat transport equations with melting and solidification model is applied. Mechanical phenomena using the stress model for a elastic-plastic range and the isotropic strengthening of material are simulated. In order to solve analyzed problem the software using the finite element method (3D problem)has been developed. The influence of the individual elements of the model on the stress field and the plastic deformation field of welded steel element is determined. A comparative analysis of the results of numerical calculations for the case: the dependence of material properties on the temperature, the inclusion of phase transformation in the solid state, the dependence of the yield strength on the phase composition of the material are made.