数字孪生驱动的航空发动机转子振动响应不平衡分析

摘要:

面向航空发动机极端服役工况下的高频垂向冲击载荷作用,因物理实体与仿真模型之间的动态闭环映射难以解析,在面对几何非线性及不平衡力-冲击载荷强耦合等复杂激励条件时,预测偏差累积显著,预测精准度不足。为此,提出基于数字孪生技术的转子振动响应不平衡分析方法。采用FPFH-ICP点云配准算法实现物理转子几何特征的高精度逆向建模,建立具有几何—物理—数据三态融合特性的高保真数字孪生体,支撑模型与实体的双向动态交互。通过耦合有限元建模与Newmark-β数值求解技术,将不平衡质量力、不平衡磁拉力、碰摩等非线性因素纳入动力学方程,从而精确刻画多场耦合激励下的振动响应特性。利用数字孪生平台的实时数据交互能力,构建基于ARIMA预测与自适应误差反馈的动态滚动修正机制,实现对不平衡振动响应的高精度、实时动态预测。实验结果表明:本文方法预测得到的位移响应最大振幅为0.3mm,冲击后轴心轨迹在X、Y方向的位移范围分别为[-0.1mm~0.1mm]与[-0.28mm~0.18mm],与实际测量结果完全吻合。在800N垂向冲击载荷作用下,转子表面裂纹数量、分布形态及磨损深度均与实际形貌高度一致。

Abstract:

The high-frequency vertical impact load under extreme service conditions of aircraft engines is difficult to analyze due to the dynamic closed-loop mapping between physical entities and simulation models. When facing complex excitation conditions such as geometric nonlinearity and strong coupling between unbalanced forces and impact loads, the cumulative prediction deviation is significant, and the prediction accuracy is insufficient. Therefore, a rotor vibration response imbalance analysis method based on digital twin technology is proposed. Using the FPFH-ICP point cloud registration algorithm to achieve high-precision reverse modeling of physical rotor geometric features, a high fidelity digital twin with geometric physical data fusion characteristics is established to support bidirectional dynamic interaction between the model and the entity. By coupling finite element modeling with Newmark - β numerical solution techniques, nonlinear factors such as unbalanced mass force, unbalanced magnetic pulling force, and impact friction are incorporated into the dynamic equations, thus accurately characterizing the vibration response characteristics under multi field coupling excitation. By utilizing the real-time data interaction capability of the digital twin platform, a dynamic rolling correction mechanism based on ARIMA prediction and adaptive error feedback is constructed to achieve high-precision and real-time dynamic prediction of unbalanced vibration response. The experimental results show that the maximum amplitude of the displacement response predicted by the method in this paper is 0.3mm. The displacement range of the axis trajectory in the X and Y directions after impact is [-0.1mm~0.1mm] and [-0.28mm~0.18mm], respectively, which is completely consistent with the actual measurement results. Under the vertical impact load of 800N, the number, distribution, and wear depth of cracks on the rotor surface are highly consistent with the actual morphology.