Perpustakaan Digital ITB

High-speed trains are ground transportation that operate at high speeds and can carry large numbers of passengers. Structural analysis is needed on high-speed trains to improve passenger safety and comfort. In this study, the modeling of welding process using finite element method (FEM) will be carried out. The welding process modeled is a multi-pass Tungsten Inert Gas (TIG) welding. ABAQUS will be used in the modeling of this welding process as it allows to perform the modeling and analyze the outcomes. The simulation of welding process will be carried out on a model geometry of 300 mm×300 mm×6 mm symmetry plate, in which the weld zone is located at the center of the plate. The welding will be simulated for the same length of the plate, from end to end, for 300 mm in weld length. The welding plate geometry follows the standards and regulations of ANSI/AWS D1.2-97, and the heat source for the welding derived from Goldak's heat source model, specifically, the double ellipsoid Goldak equivalent heat source (EHS). The heat source in this model is generated by the use of Python subroutine to assign the calculated heat flux from the heat source to sets of elements in FE simulation. The material used in this simulation is Al6061-T6 and all material properties used in this welding process modeling are temperature-dependent. This research shows that the welding process without constraints results in residual stresses and deformation of the structure. The maximum residual stress for the entire model was recorded to be 307.1 MPa at the Weld Centerline (WCL) and -49.2 MPa for the minimum stress around the Heat-Affected Zone (HAZ). The largest deformation occurs at the end of weld line surface with measured distortion of -1.714 mm. This study examines 12 different welding parameters. Based on the FE simulation, varying welding parameters result in significant impact on the residual stresses and deformation due to the thermal effects produced by these parameters. Welding processes with higher welding speeds yield higher residual stress and increase in distortion. On the other hand, as heat input increases it yields lower residual stress and larger distortion.