基于混合有限元模型的航空发动机主轴承剥落故障仿真分析方法

高保真的整机实体有限元模型可以逼真地反映航空发动机整机振动特性，但是难以考虑复杂的滚动轴承故障动力学模 型，且其计算量太大，不能胜任主轴承故障激励下的整机非线性动力学仿真。为了有效地进行发动机主轴承的故障诊断，开展了 主轴承剥落故障激励下的整机振动响应机理研究，提出了一种基于整机实体有限元模型和整机梁单元有限元模型的主轴承故障 动力学混合仿真分析方法。利用整机梁单元模型仿真分析得到主轴承故障激励下与机匣相连接的主轴承支反力，在整机实体有 限元模型中去除转子实体有限元模型，将支反力直接施加到各支承处的轴承座上，利用瞬态响应分析方法获取主轴承故障激励下 的整机振动响应，并利用整机梁单元模型进行了方法验证。结果表明：利用混合有限元仿真方法获取了航空发动机主轴承故障激 励下的仿真信号，误差均不超过1%，表明了所提出方法的正确有效性。

A Spalling Fault Simulation Method of Aeroengine Main Bearing Based on Hybrid Finite Element Model

A high-fidelity whole engine solid finite element model can realistically reflect the vibration characteristics of the aeroengine, however, it is difficult to take into account the complex dynamic model rolling element bearing fault, and its computational workload is too large to handle the whole engine nonlinear dynamic simulation under the excitation of main bearing spalling faults. In order to effectively diagnose main bearing faults, it is crucial to study the vibration response mechanism of the whole engine under the excitation of main bearing spalling faults. A hybrid simulation analysis method of main bearing fault dynamics based on solid finite element model and beam element finite element model was proposed. The support reaction forces of the main bearing connected to the casing were obtained by the simulation analysis of the whole engine beam element model, then, the rotor solid finite element model was removed from the whole engine solid finite element model, and the support reaction forces were directly applied to the bearing housing at each support, and the transient response analysis method was used to obtain the whole engine vibration response under the excitation of main bearing faults. Finally, the method was verified using the whole engine beam element model. The results show that the simulation signal under the excitation of main bearing faults can be obtained by using the hybrid finite element simulation method, with errors less than 1%, indicating the correctness and effectiveness of the proposed method.