M. M. Mashadi - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran
I. Heidari - School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran
R. Delshadi - Faculty of Mechanical Engineering, Iran University of Science and Technology, Arak, Iran

Abstract Welding is a crucial manufacturing process and widely used in industries to assemble various products including ships, automobiles, trains and bridges. Welding distortion often results in problems such as dimensional inaccuracies during the assembly and increased fabrication costs. Welding distortion during the assembly process is affected by local shrinkage due to rapid heating and cooling. The study uses the example of butt welding thin rectangular plates, the results of main interest being the temperature distribution. In this study, both the finite difference method (FDM) and finite element method (FEM) are utilized to investigate the temperature field in two plates. Firstly, 2-D symmetric finite difference model is developed to simulate the welding temperature field. Secondly, the finite element model is developed to precisely predict temperature distribution. In both the FDM and FEM, the temperature-dependant material properties are taken into account. Finally, the FDM results are compared with FEM data to investigate the effect of solution method in predicting heat distribution in thin welded structures. Also experiments are carried out to verify the simulated results. It is found that the solving method has moderate influence on predicting temperature field. The maximum magnitude of temperature at nodes near the weld line in FDM is less than that in FEM. Also, temperature gradient in FDM is larger than that in FEM, and therefore results in a more critical welding condition. So in conservative designs FDM is more desirable. However, FEM has advantage in reducing the solving time. The effectiveness of the proposed FEM is confirmed using experimental values.

Finite Difference Method; Finite Element Method; Experiment; Temperature Field; Welding