Advanced welding methods like Friction Stir Welding (FSW) continue to emerge along with methods for reducing the structures weight. Since the design of the structures is becoming complex, the need for welding of complicated geometries is increasing. However, finite element modelling of FSW is still limited to the flat welding seams. On the other hand, since significant thermal energy and high stress is generated during FSW, thermomechanical analysis of FSW plays a significant role in determining the quality of the weld. Thus, there is a need investigate the thermomechanical analysis of FSW with a curved welding path. Thermal behavior of the flat and the curved FSW is compared in this paper. The results indicated that, the temperature and stress behavior is approximately asymmetric in different sides of the tool. Moreover, as the welding seam becomes more complex, the size and the shape of the different welding zones significantly changes. It is also observed that at a same condition, the temperature and the stress of the curved model is always lower in comparison with the flat model due to the lower penetration of the pin inside the workpiece. Finally, verification and validation of the results is done by using the experimental and published data.

中文翻译：

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平面搅拌摩擦焊和弯曲搅拌摩擦焊（FSW）热力学行为的比较

诸如搅拌摩擦焊（FSW）之类的先进焊接方法与减轻结构重量的方法一起不断涌现。由于结构的设计变得复杂，因此对复杂几何形状的焊接的需求也在增加。但是，FSW的有限元建模仍然仅限于平焊缝。另一方面，由于在FSW期间会产生大量的热能和高应力，因此FSW的热机械分析在确定焊缝质量方面起着重要作用。因此，需要研究具有弯曲焊接路径的FSW的热力学分析。本文比较了平面和弯曲FSW的热行为。结果表明，温度和应力行为在工具的不同侧面近似不对称。此外，随着焊缝变得越来越复杂，不同焊接区域的尺寸和形状会发生显着变化。还可以观察到，在相同条件下，由于销钉在工件内部的渗透率较低，因此与扁平模型相比，弯曲模型的温度和应力始终较低。最后，使用实验数据和公开数据对结果进行验证和确认。