The present article discusses the simulation and mathematical modelling of GTAW for various parameters of single and double V-groove butt joint welds. The chosen materials are EN 10025steel(grade S295) and D36 ship building steel, owing to their wide industrial applications and corrosion resistive nature. The simulation modelling was carried out at 90°, 60°, 45° and 30° groove angles for both similar and dissimilar base metals to predict the deformation, residual stress distribution, heat flux, and nodal temperature using ABAQUS software package. A subsequent mathematical model was developed using MATLAB tool to further predict the temperature distribution and total stress concentration at any localized nodal point. The model can be used to obtain optimal weld parameters such as weld, speed torch temperature, current and voltage. The obtained results were plotted to attain the clear conclusion over the results. The results under simulation showed 45° to be the most effective angle for both Single-V and Double-V grooved butt joints. © Faculty of Mechanical Engineering, Belgrade.