旋转弯曲微动疲劳裂纹萌生及扩展机理和寿命预测方法研究

项目名称： 旋转弯曲微动疲劳裂纹萌生及扩展机理和寿命预测方法研究

项目编号： No.51305362

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 刘建涛

作者单位： 西南交通大学

项目金额： 25万元

中文摘要： 旋转弯曲微动疲劳是指相互接触的旋转构件在外加扭转和弯曲载荷下接触面间发生微动损伤，促使构件过早萌生裂纹并扩展失效的现象，至今其损伤机理研究尚不系统。本课题以机车电机轴/小齿轮轴为背景，研究旋转弯曲微动疲劳裂纹萌生及扩展机理和寿命预测方法。依据结构实际工况和失效分析，提取模型的材料、几何、外载等信息，建立系统的动态控制方程及弱形式；结合单位分解原理，建立模拟旋转弯曲微动疲劳问题的扩展有限元法；进而基于FerContact/View开发考虑动载效应的旋转弯曲微动疲劳裂纹萌生和扩展专用模拟程序。结合裂尖处应力等模拟结果和断面微观分析，揭示旋转弯曲微动疲劳失效机理，建立裂纹扩展准则和寿命预测模型。最后，结合旋转弯曲微动疲劳试验，验证失效机理和寿命预测模型的正确性。本研究具有深化微动疲劳体系的理论意义，且有重要的工程应用背景，对机车轮轴、航空发动机涡轮轴等部件的损伤防护和寿命预测具有重要应用价值。

中文关键词： 旋转弯曲微动；非完美界面；自动建模；相场方法；非均质性

英文摘要： Rotary bending fretting fatigue refers to the failure phenomenon that the fretting damage occurs on the contact surfaces of rotating components under external cyclic torsion and bending loads, and promotes a relative early crack nucleation and propagation. So far, the failure mechanism of this phenomenon has not been studied systematically. This project mainly concentrates on the investigation of the nucleation and propagation mechanism as well as the life prediction method of rotary bending fretting fatigue cracks in the context of traction motor shaft and pinion shaft of locomotive. Firstly, by analyzing the actual working condition and failure process, the material property,geometrical parameter, external loads and so forth of the structure are extracted, and the dynamic government equation as well as the weak form of the traction motor shaft and pinion shaft system is established accordingly. Afterwards, combined with the partition of unity theory, an extended finite element method (XFEM) in consideration of dynamic loading effects is established to simulate the fretting fatigue crack nucleation and propagation process under rotary bending loads and a special program is developed based on FerContact/View simultaneously. After that, the stress states around the crack tip from the crack nucleation to the criti

英文关键词： Rotary bending fretting；imperfect interface；Automatic modeling；Phase method；Heterogeneity