Experimental Investigation and Numerical Analysis of Thermal Fields and Residual Stresses in Multi-pass GTA Welding of AA 6061T6 Plates

Abstract

Welding is one of the most widely used materials joining processes in the industries. Plates of different thicknesses used for the fabrication of components can be welded using multi-pass welding, depending upon the applications. However, residual stresses are induced in the welded joints due to the rapid heating and cooling, which leads to inhomogeneous distribution of dimensional changes and consequently the failure of welded joint occurs. This manuscript aims to predict temperature distribution and residual stresses during multi-pass butt joint on gas tungsten arc welding (GTAW) of aluminum alloy (AA) 6061T6 weldments. Transient thermal analysis and mechanical stress contour in three dimensions have been estimated considering three modes of heat transfer, i.e., conduction, convection, and radiation. Temperature-dependent properties such as thermal conductivity, heat capacity, yield stress, elastic modulus, and thermal expansion are employed in the welding simulations. The experimental results of temperature distribution in AA 6061T6 weldments are validated using ANSYS 18.1.