Abstract:

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 aero-engines 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.

Key words: base random vibration excitation, fluid pressure pulsation excitation, aero-engine, L-shaped pipeline, dynamics modeling