【摘要】 以某风电场1.5 MW风电机组齿轮箱第三级小齿轮为研究对象，针对齿轮在工作过程中出现裂纹并断裂的问题，运用线弹性断裂力学理论结合有限元法计算的方法，准确计算了裂纹前缘各点的应力强度因子，从后处理结果中得知I型应力强度因子占主导地位。在此有限元模型基础上，分析载荷、裂纹长度以及位置对I型应力强度因子的变化规律。结果表明，随着载荷的逐渐增大，齿轮齿根三维裂纹前缘应力强度因子曲线整体呈现增大的趋势；当齿轮齿根的初始三维裂纹长度增加时，应力强度因子曲线在两端即靠近齿面的位置基本保持不变，而在中间即裂纹深处随着三维裂纹长度的增加而增大。当裂纹的初始位置越靠近轮齿中间部位时，齿轮的三维裂纹应力强度因子整体呈现增大的趋势，并且增加幅度逐渐变大。更多还原

【Abstract】 The third stage small gear of a 1.5 MW wind turbine gearbox in a specific wind farm is the subject of study. Addressing the problem of gear cracking and fracture during operation, the method of combining linear elastic fracture mechanics theory with finite element method for calculation is utilized, the stress intensity factors at different points along the crack front are accurately computed. From the post-processing results, it is revealed that the mode I stress intensity factor predominates. Based on this finite element model, the variation in mode I stress intensity factor with load, crack length, and position are analyzed. The results show that with the gradual increase in load, the stress intensity factor curve at the leading edge of the three-dimensional crack at the gear root generally increases; as the initial three-dimensional crack length at the gear root increases, the stress intensity factor curve remains relatively constant at both ends near the tooth surface, while it increases in the middle, i.e., at the depth of the crack, with the increase of the three-dimensional crack length. When the initial position of the crack is closer to the middle part of the tooth, the overall trend of the stress intensity factor for the gear′s three-dimensional crack increases,and the magnitude of increase gradually becomes larger.更多还原