航空发动机轮盘模拟件裂纹预制分析与试验研究

Theoretical Analysis and Experiment Research for Prefabricating Crack in the Aero-engine Disk Simulator

航空事故数据显示,航空发动机轮盘运行可靠性已成为飞行安全的决定性因素之一,及时有效的发现并排除轮盘结构缺陷有着非常重大的实际价值。为了给轮盘损伤识别研究提供必要基础,提出一种可行的轮盘结构裂纹预制方法。为此,首先对轮盘模拟件中V型缺口根部应力奇异性分布特征进行了理论分析;其次,根据载荷条件和几何特征提出载荷等效方法,并进行了应力状态及疲劳分析。为了验证所提裂纹预制方法的可行性,对预制模型进行疲劳试验研究。试验结果显示,相应位置处x方向应力和疲劳循环载荷次数相对误差约为2.7%和12.7%。同时证实所采取的裂纹预制与相应数值分析方法可以应用于航空发动机轮盘损伤识别方法的研究中。

Data of aviation accidents shows that the operation reliability of aero-engine disks has been one of the determining factors for the safe flight of airplane. Therefore, it is valuable and important to diagnosis the disk structural defects in time. To provide the necessary foundation for damage identification of disks, a feasible prefabricating crack method for disk structure is proposed. Firstly, the singularity distribution characteristics in root stress of the V notch in the disk simulator are analyzed in theory sufficiently. Secondly, an equivalent load method is proposed based on the loading conditions and geometrical features. The stress condition and fatigue life are also analyzed. Finally, to verify the feasibility of the proposed method for prefabricating crack, a fatigue experiment is carried on. The experiment results show that the relative errors of stress in x direction and the number of fatigue loading cycles are 2.7% and 12.7% respectively, which demonstrate the proposed method for prefabricating crack and corresponding numerical analysis method can be used for damage identification of aero-engine turbine disks.