Modelling and Simulation of Transient Thermal Stress Distribution across AISI 1018 Flat Plates at Variable Welding Temperature Regime

Abstract

In recent times, failure in structural components has been attributed to a lack of improper understanding of material behaviour under welding temperature, during which thermally induced stresses are trapped (residual stress) within the weldment. This study investigated the effects of variable Tungsten Inert Gas (TIG) welding temperature across AISI 1018 flat plates concerning thermal stress distribution using experimental and Finite Element Method at welding temperatures ranging from 6800-9600^oF. Thermally-induced stresses of 4244.373 and 4345.894 MPa were obtained from both FEM and Experimental process at a welding temperature of 680^oF while the thermally induced stress values at a higher welding temperature of 9600^oF for FEM and experimental process were obtained as 10786.858 and 12124.269 MPa. The study revealed a significant correlation established between the experimentally induced thermal stress distribution and the FEM-induced thermal stress distribution. Moreover, thermally induced stresses were observed to increase as the welding temperature also increased and vice versa. Hence, the FEM approach employed in the study can be adopted as a novel technique for modelling, prediction and control of welding temperature to prevent intense welding heat from translating into detrimental defects due to creep mechanism (thermal loading temperature on material geometry), which may result in untimely failure of component materials in welding-related applications.