For load-carrying fillet welded joints, the fracture due to the crack propagation near the root takes place frequently in practical engineering. Given the essential role of welded joints in Tee configurations with double-sided and single-sided welds, the assessments of the fracture behavior of such joints and the stress intensity factors (SIFs) related to the crack opening (mode-I) fracture and the sliding or shear (mode-II) fracture are the main topic of this study. A planar structure finite element model incorporating the crack body with the singularity in front of the crack tip is developed to simulate the failure at weld root due to the presence of non-penetrating regions. Effects of the fillet angle (θ_f), the effective weld throat thickness (h_e), the thicknesses of the main plate (t_p) and the cross plate (t_c) on SIFs are analyzed. The results show that the effect of h_e/t_p has a significant effect on SIFs and becomes more obvious as the crack is propagated at the weld root and inside the fillet weld. The increase of θ_f significantly amplifies the SIFs especially for the fracture mode related to K_II. The effect of t_c/t_p is insignificant for the fracture mode related to K_I while its amplification results in a moderate increase of K_II especially for the single-sided fillet welds.

对于承载角焊缝，实际工程中经常发生根部附近裂纹扩展引起的断裂。考虑到焊接接头在具有双面和单面焊缝的三通配置中的重要作用，对此类接头的断裂行为以及与裂纹张开（模式-I）断裂相关的应力强度因子 (SIF) 的评估以及滑动或剪切（II 型）断裂是本研究的主要主题。开发了一个包含裂纹体和裂纹尖端前奇异点的平面结构有限元模型，以模拟由于非穿透区域的存在而导致的焊缝根部失效。角角 ( θ _f )、有效焊喉厚度 ( he _e），主板（的厚度吨_p）和所述横向板（吨_Ç上SIFS）进行了分析。结果表明，h _e / t _p的影响对 SIF 有显着影响，并且随着裂纹在焊缝根部和角焊缝内部扩展而变得更加明显。θ _f的增加显着放大了 SIF，特别是对于与K _II相关的断裂模式。t _c / t _p的影响对于与K _I相关的断裂模式不显着，而其放大导致适度增加K _II特别适用于单面角焊缝。