Dynamic modeling and experimental verification of an L-shaped pipeline in aero-engine subjected to base harmonic and random excitations

Abstract

The aero-engine pipeline is inevitably subjected to base harmonic and random excitations during operation, but the vibration response analysis of the aero-engine pipeline under base random excitation has been rarely incorporated in the open research. Therefore, a dynamic model of an L-shaped pipeline combining the transfer matrix method (TMM) and lumped parameter method is proposed to solve the vibration response of the aero-engine pipeline under base harmonic and random excitations, and the natural and response characteristics of the pipeline are investigated by simulation and experiment. Firstly, the transfer matrix of the L-shaped pipeline is derived, and the natural frequencies and the corresponding mode shape vectors are obtained. Then, combined with the lumped parameter method, the transfer matrix of the L-shaped pipeline under base harmonic excitation is reconstructed and its frequency domain response is solved. On this basis, the virtual excitation method is introduced to address the dynamic responses of pipelines under base random excitation. Finally, the vibration test system for the L-shaped pipeline subjected to base excitation is built, and the vibration response solution method is verified through the comparison of simulation and experimental results. The work can provide an effective solution for the vibration response analysis of aero-engine pipelines under base harmonic and random excitations.