多源激励下航空发动机L型管路动力学建模与验证

Dynamics modeling and validation of L-shaped pipeline in aero-engine under multi-source excitations

从解析分析角度,创建了考虑基础随机振动和流体压力脉动影响的多源激励下受卡箍约束的航空发动机L型管路的动力学模型。基于Timoshenko梁理论和传递矩阵法,推导获得了管路系统分别在轴向、横向以及轴向扭转方向对应的振动平衡方程,实现了充液后该管路系统固有特性的求解。提出了频域倍频能量法构造流体压力脉动函数的激振力,在采用虚拟激励法模拟基础随机振动载荷后,将2种激励方式同时加入到平衡方程中,在上述复杂的多源激励条件下,成功求解获得管路的振动响应。最后,组建了多源激励下航空发动机管路振动测试系统,在不同的激励条件下开展了验证测试,证明了所提出的理论模型及其分析结果的有效性,其对于复杂激励载荷下航空航天多种管路系统的动态响应预报与减振设计具有重要参考价值。

From the perspective of analytical analysis,a dynamic model of an L-shaped pipeline in aero-engine with clamp constraints under multi-source excitations is established,with consideration of base random vibration excitation and fluid pressure pulsation excitation loads.Based on the Timoshenko beam theory and the transfer matrix method,the vibration equilibrium equations of such a pipeline system in the axial,transverse,and axial torsion directions are derived,with the inherent properties of the pipeline system filled with the fluid solved.A multiple-frequency energy method in the frequency domain is proposed to construct the excitation force of the fluid pressure pulsation function.Moreover,a virtual excitation method is adopted to simulate the base random vibration load.After the two kinds of excitation loads are added to the equilibrium equations,the vibration response of the pipeline is successfully solved under the above complex multi-source excitation conditions.Finally,a vibration test system of pipeline systems in aeroengines with multi-source excitation is established,and validation tests are performed under different excitation conditions.The effectiveness of the proposed theoretical model and its analysis results is proved,providing important reference for the prediction of dynamic response and anti-vibration design of various pipeline systems in aerospace under complex excitation loads.