Prediction of the Temperature Behaviour During Friction Stir Welding (FSW) Using Hyperworks ® Bahman Meyghani 1 , Mokhtar B. Awang 2(B ) , and Reza Teimouri 3 1 Institute of Materials Joining, Shandong University, 17923, Jingshi Road, Jinan 250061, China 2 Department of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi PETRONAS (UTP), 32610 Bandar Seri Iskandar, Perak Darul Ridzuan, Malaysia Mokhtar_awang@utp.edu.my 3 Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran Abstract. Fundamentally, heat is needed during friction stir welding (FSW) for joining materials together. This heat is usually produced by friction force and material deformation. Therefore, friction coefficient is a significant factor and in order to increase the efficiency and the quality of the simulated model, there is a need to explore it accurately. However, previous studies used constant values of the friction coefficient resulting in inaccuracy of the model. This paper proposes, a mathematical formulation for predicting temperature dependent values of the friction coefficient using coulomb friction and von Mises yield laws. Then, the friction coefficient values are used to simulate a finite element model. HyperMe- sh® and HyperView® solvers have been employed from Altair Hyperworks® to simulate the process. The results of the model showed that, the temperature at the shoulder surface is always higher than the pin area, thus the heat generated by shoulder is found to be higher around 60 °C. Furthermore, higher temperature at the advancing side (around 30 °C) was obtained. Finally, the model is verified to show the accuracy of the predicted friction coefficient values and the results of the finite element model. Keywords: Friction stir welding · Heat · Friction force · Material deformation · Friction coefficient · Finite element model 1 Introduction There is an increasing need to reduce structures weight, especially for the aircraft pan- els and aerospace industries. Advanced welding techniques play a significant role in manufacturing of these lightweight structures. Friction stir welding (FSW) is one of the most important and relatively new solid state welding methods which was invented and patented in the last decades [1–3]. FSW was developed in the automotive industry as an alternative method for welding of aluminium sheets in 2001 [4, 5]. Nowadays, FSW can be used to join a variety of materials without the use of filler material and the process currently is using in a lot of industrial applications, such as railway, marine, © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021 M. Awang and S. S. Emamian (Eds.): Advances in Material Science and Engineering, LNME, pp. 119–130, 2021. https://doi.org/10.1007/978-981-16-3641-7_16