目的 建立钛合金材料的疲劳寿命预测模型,并通过实验研究验证此模型在预测滚磨光整加工后钛合金材料疲劳寿命的可行性。方法 采用有限元软件ABAQUS和疲劳分析软件FE-SAFE,通过有限元仿真和多元正交回归实验的方法,研究了粗糙度以及残余应力对TC4钛合金疲劳寿命的影响规律。结果 拟合出疲劳寿命与粗糙度以及残余应力的关系方程式,进而通过实验验证了仿真结果以及公式的正确性。结论 滚磨光整加工后,表面粗糙度R_z值由加工前的3.16变为1.69,残余应力由拉应力50 MPa变为压应力-228 MPa,疲劳寿命从加工前的28 083次提高到39 510次,提高了40.6%,实验结果与仿真结果相比,误差在5%左右,证明仿真结果的可行性,为滚磨光整加工钛合金提供了疲劳寿命预测模型。
The work aims to establish a fatigue life prediction model for titanium alloy and verify feasibility of this model in predicting titanium alloy fatigue life after barrel finishing by virtue of experimental study. Influencing law of roughness and re- sidual stress on TC4 titanium alloy fatigue life was studied by virtue of finite element simulation and multivariate regression or- thogonal experiment. Relation equation among fatigue life, roughness and residual stress was simulated, correctness of the si- mulation results and equation were fiarther validated by experiments. After the barrel finishing, the roughness of TC4 board changed from Rz=3.16 to Rz= 1.69. The initial residual tensile stress turns into compressive residual stress from 50 MPa to -228 MPa. The fatigue life increases from 28,083 to 39,510 times and has increased by 40.6%. Compared with the results of simula- tion, the error is about 5%, testifying feasibility of simulation results. Therefore, a fatigue life prediction model is provided for titanium alloys subject to barrel finishing.