Compared with thick plate welded joint, the welding joint of thin plate will produce initial deformation due to its low bending rigidity. The existence of initial deformation will cause the welded structure to produce secondary bending effect, which will produce greater stress magnification effect at the weld toe and seriously affect the fatigue strength of thin plate welded joints. Therefore, based on the correction formula of thick plate, considering the influence of initial deformation and geometric nonlinearity of thin plate, this paper deduces the stress magnification factor formula at the weld toe of T-shaped and cruciform specimens. The accuracy of the revised formula is further verified by comparing the notch stress calculated by the modified formula with the FE results. Finally, the modified formula is applied to the notch stress and fatigue evaluation of typical thin plate welded joints respectively. The results show that the proposed notch stress calculation formula can fully consider the stress amplification effect of thin plate structure, and can be used to quickly evaluate the notch stress field and fatigue strength of thin plate welded joints.

与厚板焊接接头相比，薄板焊接接头由于其较低的弯曲刚度会产生初始变形。初始变形的存在将使焊接结构产生二次弯曲作用，这将在焊趾处产生更大的应力放大作用，并严重影响薄板焊接接头的疲劳强度。因此，根据厚板的修正公式，考虑薄板的初始变形和几何非线性的影响，推导了T形和十字形试件焊趾处的应力放大系数公式。通过将修改后公式计算出的缺口应力与有限元结果进行比较，可以进一步验证修改后公式的准确性。最后，修改后的公式分别应用于典型的薄板焊接接头的缺口应力和疲劳评估。结果表明，所提出的缺口应力计算公式能够充分考虑薄板结构的应力放大效应，可用于快速评估薄板焊接接头的缺口应力场和疲劳强度。