中文摘要：

从齿轮内部存在缺陷这一事实出发，研究不同载荷、不同缺陷位置对齿轮寿命的影响．根据齿轮无损探伤验收标准设定的初始缺陷，应用边界元分析软件FRANC3D（fractureanalysiscodein3dimensions）计算了裂纹前沿不同位置处的应力强度因子，对齿轮在不同载荷条件下进行裂纹扩展的仿真，得到不同载荷条件下载荷循环次数与裂纹长度关系曲线及齿轮寿命与齿根应力幅值曲线．

英文摘要：

Taking account of the fact that there are defects in the interior of a gear, the influence of the different loads and locations of the defects on the gear life was investigated. The Initial defect was set ac- cording to gear nondestructive flaw detection acceptance criteria. The boundary element analysis software- FRANC3D was used to calculate the stress intensity factor at different locations of the crack front and sim- ulate the crack propagation in different gear loading conditions, so that the relationship curve of load cycles versus crack length and the curve of gear life versus tooth root stress amplitude were obtained under differ- ent load conditions.