文档介绍：南京航空航天大学
硕士学位论文
燕尾榫结构微动疲劳寿命预测方法研究
姓名:杨万均
申请学位级别:硕士
专业:航空宇航推进理论与工程
指导教师:崔海涛
20070301
燕尾榫结构低周微动疲劳寿命研究
摘要
微动损伤是工程中最为常见、最普通的一种损伤形式,微动疲劳损伤可以加
速受微动作用构件的表层疲劳裂纹的萌生和扩展,降低构件的寿命,甚至造成灾
难性的事故。目前,国内大量的工作都集中在微动损伤机理的研究,对微动疲劳
寿命的预测还处于研究和探索阶段,因此,研究微动损伤及其寿命预测具有重要
的工程应用价值。
发动机叶片与轮盘连接处的榫结构由于受到复杂的载荷,因而导致严重的微
动损伤发生。本文首先对微动磨损的机理以及寿命预测方法给予简要的介绍,在
此基础上,基于 ANSYS 软件建立了燕尾榫结构的有限元模型,通过燕尾榫结构的
强度分析,获得了榫槽和榫头接触面上有关微动特征参数的分布趋势,据 SWT 参
数预测了微动裂纹萌生的位置,预测结果与试验结果相吻合,并且基于 Coffin—
Manson 方程,获得了一种改进的微动疲劳寿命预测模型。其次,根据燕尾榫结
构微动疲劳试验中获得的应变监测曲线,基于有限元计算确立了微动疲劳裂纹长
度与试验寿命之间的关系,并据此给出了燕尾榫结构裂纹长度为时的微动
疲劳试验寿命,基于该试验寿命验证了本文所建立的微动疲劳寿命预测模型。最
后,对影响微动疲劳的摩擦系数、底角等有关参数进行了分析。结果表明:在工
程实际运用中,可以通过减小摩擦系数来提高燕尾榫结构的疲劳强度。此外,燕
尾榫底角选择在 40~45 度左右具有较好的疲劳强度,微动磨损以及应力集中程度
较轻,其微动疲劳寿命也较长。

关键词:燕尾榫,微动损伤,微动疲劳,寿命预测,Coffin—Manson 方程,
SWT 参数

IV
南京航空航天大学硕士学位论文
ABSTRACT
Fretting damage is one of the mon damage in engineering. It occurs at
the contact surface where exist relative micro-slip less than 300 µm and vertical
pressure between ponents. It usually makes the initiation and growth of the
crack rapidly at the contact area, reduces the fatigue strength and even causes security
accidents. Many failures of dovetail joint in aero-engine are found under fretting
fatigue circumstance. At present, the major work are focused on the fretting damage
mechanism. It’s important to research fretting fatigue life prediction of the dovetail
joint.
In this thesis, firstly some mainly fretting fatigue damage mechanisms were
introduced, and it was gotten that the fretting experiment life of the dovetail joint
according the S-N curve of the fretting fatigue experiments. The finite element model
of dovetail joint was created by ANSYS software, and the stress field of the contact
surface was gotten. The local important fretting fatigue parameters were analyzed, and
the SWT parameter was used to predict the position of crack initiation at the contact
surface, the result was concide wit