基于XFEM的谐波减速器柔轮裂纹扩展行为研究  

Research on Crack Propagation Behavior of Flexspline in Harmonic Reducer Based on XFEM

作　　者：薛栋文 徐洋[1] 解国升 赵言正[2] 刘积昊[2] Xue Dongwen;Xu Yang;Xie Guosheng;Zhao Yanzheng;Liu Jihao(College of Mechanical Engineering,Donghua University,Shanghai 201620,China;School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]东华大学机械工程学院,上海201620 [2]上海交通大学机械与动力工程学院,上海200240

出　　处：《机械传动》2022年第10期37-41,48,共6页Journal of Mechanical Transmission

基　　金：国家自然科学基金天文联合基金项目(U1831123);国家自然科学基金青年科学基金(51803122);国家重点研发计划(2017YFB1300603)。

摘　　要：柔轮的疲劳开裂是引起谐波减速器精度下降和设备可靠性降低的重要原因。以某型号谐波减速器为研究对象,基于壳体力矩理论建立柔轮等效模型,确定柔轮应力集中的参数;通过有限元仿真,获取柔轮应力最大结点位置,并引入微小角裂纹;通过分析裂尖应力场参量,描述了柔轮裂纹扩展的能力和趋势;基于最大主应力损伤演化准则,通过扩展有限元方法(XFEM)模拟裂纹扩展差异性行为,并搭建加速寿命实验台,验证了扩展有限元模型的正确性。结果表明,裂纹扩展路径与有限元结果吻合;柔轮齿根部及筒体与凸缘交界处应力集中,最易出现疲劳裂纹;裂纹扩展路径受增量步与应力分布影响;应力分布随裂纹扩展程度变化,易引起扩展路径出现偏折现象。Fatigue cracking of the flexspline is an important cause of the decrease in accuracy and equipment reliability of the harmonic reducer.A model of harmonic reducer is taken as the research object,and an equivalent model of the flexspline is established based on the theory of shell moment to determine the parameters of stress concentration in the flexspline.Through finite element simulation,the location of the maximum stress node of the flexspline is obtained,and tiny angular cracks are introduced.By analyzing the crack tip stress field parameters,the ability and trend of the flexspline crack expansion are described.Based on the maximum principal stress damage evolution criterion,the differential behavior of crack expansion is simulated by the extended finite element method(XFEM),and an accelerated life experiment bench is built to verify the correctness of the extended finite element model.The results show that the crack expansion path matches with the finite element results;the stress concentration at the root of the flexspline teeth and the junction of the barrel and flange is prone to fatigue cracking most;the crack expansion path is affected by the incremental step and stress distribution;the stress distribution varies with the degree of crack expansion,causing a bias in the expansion path.

关 键 词：谐波减速器 柔轮 扩展有限元法 裂纹扩展 

分 类 号：TH132.46[机械工程—机械制造及自动化]