超声载荷下TC4钛合金的疲劳寿命分析  

Fatigue life analysis of TC4 titanium alloy under ultrasonic loading

作　　者：苏胜 郭利军[2] 张东博 高琦[3] 王彤宇[1] 

机构地区：[1]长春理工大学机电工程学院,吉林长春130022 [2]凌云科技集团有限责任公司,湖北武汉430040 [3]中国科学院声学研究所东海研究站,上海201815

出　　处：《声学技术》2018年第1期57-61,共5页Technical Acoustics

基　　金：国家自然科学基金项目(11474042;11774382;11574348)

摘　　要：通过计算裂纹尖端应力强度因子及疲劳裂纹扩展速率da/d N,由C.Paris模型推导出安全寿命Nf,由Bathias公式计算"哑铃"状钛合金试样的裂纹扩展寿命。通过理论计算和有限元分析超声疲劳"哑铃"状试样,得出应力最大位置。利用有限元仿真和实验数据分析TC4钛合金疲劳寿命。在20 k Hz的超声疲劳试验中,试样的断口位置表明:TC4钛合金材料内部缺陷是试样萌生裂纹使断裂位置偏离最大应力处的主要原因。并得出疲劳裂纹萌生阶段寿命决定"哑铃"状试样的疲劳寿命。The position of maximum stress in the ultrasonic fatigue test of dumb-bell shaped TC4 titanium alloy specimen is determined by theoretical calculation and the finite element simulation. In the 20 kHz ultrasonic fatigue test, the fracture position of the specimen shows that the internal defect of TC4 material is the main reason of the crack initiation to make the fracture position deviated from the maximum stress position. The fatigue life of TC4 is analyzed by finite element simulation and experimental data. By calculating the stress intensity factor at crack tip and the fatigue crack growth rate da/dN, the safety life Nf is derived from the C.Paris model. The Bathias formula is used to calculate the crack propagation life of the dumb-bell shaped specimen, and the fatigue life of the specimen is determined by the crack initiation life.

关 键 词：疲劳寿命 应力强度因子 有限元 断裂力学 

分 类 号：TB553[理学—物理]