Numerical Modelling of Thermal and Structural Strain in Laser Welding Process / Modelowanie Numeryczne Odkształceń Cieplnych I Strukturalnych W Procesie Spawania Techniką Laserową

This work concerns numerical modelling of thermal and structural strain, resulting in heating and cooling of laser butt-welded joints. Numerical analysis of strain is carried out in Abaqus FEA. Through the use of additional author’s subroutines, the structural strain caused by phase transformations during heating and cooling of welded elements is taken into account in the analysis. V.I. Machnienko models as well as Continuous Heating Transformation (CHT) and Continuous Cooling Transformation (CCT) diagrams for S355 steel are implemented into UEXPAN subroutine in order to determine the kinetics of phase transformation in the solid state. The model takes into account thermomechanical properties of the base material varying with temperature. The paper presents results of numerical simulation of temperature field, predicted structural composition, thermal and structural strain in laser butt-welded joints.