International Congress on Advances in W elding Science and Technology for Construction, Energy and Transportation Systems (AWST - 2011) 24-25 October 2011, Antalya, Turkey AWST-11/119 Thermomechanical Analysis of Arc Welded Joint by Finite Element Method N. Akkuş 1,a , E. Toptas 2,b , O. Topal 3,c 1 Gedik University, Cumhuriyet Mahallesi, E-5 Yanyol No:29 Kartal, Istanbul 2 Marmara University, High Collage for Technical Sciences, Goztepe, Istanbul 3 Marmara University, Institute of Pure Sciences, Goztepe Campus, Istanbul a nihat.akkus@gedik.edu.tr, b etoptas@marmara.edu.tr, c omurtopal@hotmail.com Abstract The aim of this study is to realize a simulation of arc welding using Finite Elements Analysis (FEA). In general, thin steel metals are used in the automotive and machine industries and the distortion after arc welding is more evident, because of the lack of quality in the product this creates problems. It is important to predetermine these problems before welding process. One way of the prediction of welding process is “try and see”. But this may need high cost and time. Therefore, Finite Element Method is very often used today to monitor and predict the welding process. In order to do this, MSC.Marc-Mentat program was used to simulate the arc welding process by 3-D modeling in terms of temperature distribution and distortions. Then, the results of experiments were compared to that of obtained in the simulation. The comparison of the results revealed familiarity between the presented FE model and experiments Keywords: Arc Welding, Welding Simulation, Finite Element Method 1. Introduction Arc welded joint is one of the most important joining methods in manufacturing industry. Accordingly, steel and steel products are the most commonly used products in the welding techniques. Material composition and temperature variations in welds and parent metals have important effects on material characteristics, residual stresses, dimensional and shape accuracy of welded fabrications. Residual stresses are produced in weldments due to mismatching and non-uniform distributions of plastic and thermal strains. These consequences deteriorate the welding quality and affect the production life in the places where welding steels are used. On the other hand, increasingly, the design of engineering components and structures relies on the achievement of small tolerance. For these reasons, prediction and control of welding deformation have become of critical importance. In welding production, we need to know how the material responds to the thermal effects. There are various methods to ascertain residual stresses, distortions, and temperatures such as heat measurement and hole method to understand residual stress. However, these methods are costly and require a great deal of time. Therefore, FEA will be extremely beneficial for us in conducting these evaluations. Welding process simulation is one of the most crucial topics of the related literature, and there are various researches conducted on this issue. The application of different welding methods and sample usage that is not obtained with the conventional sampling methods decrease the number of researches that are directly related with the welding process simulations. Some of those researches are discussed below. Teng and Ling [1] determine residual stresses of the steel plates in single-pass arc welding by using ANSYS finite element techniques. Additionally, welding speed, sample size, external mechanical constraints and the impacts of preheating on residual stresses is discussed. Meo and Vignjevic [2] investigate the temperature distributions, distortions and residual stress fields of the welded aluminum plates during the welding processes. By using finite element methods, a numerical analysis of the welding process is conducted, and the results of this numerical analysis are compared with the outcomes of the experiments. In the study of Wu et al. [3], the butt-welded joint process of two steel plates is simulated. Finite Element Method (FEA) is conducted in two steps. First, to determine the temperature distribution during the welding process, a non-linear transient thermal analysis is conducted. The stress analysis is developed with the temperatures obtained from the thermal analysis. Jang et al. [4] examine the mechanical features of the multi-pass welding, and simulate welding deformations and residue stresses by using finite element analysis. Zu and Chao [5] carried out a detailed three-dimensional non-linear thermal and thermo-mechanical analysis by using finite element simulation code (WELDSIM). Teng et al. [6]