飞机管道颗粒碰撞阻尼器设计与试验验证

飞机管道振动超标是严重威胁飞机飞行安全的重要故障，降低飞机管道振动水平，对于提高飞机可靠性和安全性具有重要意义。针对难于施加管道卡箍约束的飞机管道结构的减振问题，设计了一种基于颗粒碰撞阻尼技术的管道减振器。该减振器通过特定的结构设计，在不影响现有管道结构的基础上，很方便地安装到管道上进行减振。其减振原理是基于减振器内部的颗粒碰撞而导致的能量耗散，从而提高管道结构的阻尼效应。因此，将此颗粒碰撞阻尼器安装在振动管道上，在管道发生共振的情况下，管道振动峰值将明显降低。本文基于所设计的管道减振器，利用振动台试验研究了颗粒填充率对减振效果的影响，发现改变阻尼器内部颗粒的填充率，管道的振动随颗粒填充率的增加有先减小后增大的趋势，同时利用EDEM颗粒流仿真软件计算了减振器振动过程中颗粒的能量耗散情况，发现颗粒能量耗散速率最大时所对应的颗粒填充率与试验过程中管道振动加速度降到最低时所对应的颗粒填充率达到了一致，仿真结果与试验结果取得了很好的一致性。最后，将所设计的颗粒阻尼减振器安装在液压动力源管道上进行实际减振试验，测试了在安装减振器前后，试验管道在X、Y、Z三个方向的振动加速度，经过对比分析，发现安装颗粒阻尼减振器后，液压管道的压力脉动频率下的振动水平得到了明显抑制，试验结果充分表明了本文所设计的飞机管道颗粒减振器的有效性和实用性。

Design of a particle damping absorber and experimental study on vibration damping of the pipe

Aircraft pipeline vibration is an important fault that seriously threatens flight safety. It is of great significance to reduce the vibration level of aircraft pipeline and improve the reliability and safety of aircraft. Aiming at the vibration reduction of aircraft pipeline structure which is difficult to be constrained by pipe clamps, a pipeline vibration absorber based on particle impact damping technique is designed. Through ingenious structural deign, the vibration absorber is conveniently clamped to the existing pipeline without affecting the existing pipeline structure. Based on the energy dissipation caused by the particle collision inside the damper, the damping effect of the pipeline structure is improved. Therefore, if the particle impact damper is installed on the vibrating pipe, the peak vibration of the pipeline will be significantly reduced when the pipeline resonates. In this paper, the influence of the particle filling ratio on damping effect is studied by shaking table test, and it is found that the vibration of the pipeline tends to decrease first and then increase with the increase of particle filling ratio. At the same time, using EDEM particle flow simulation software, the energy dissipation of particles in vibration process of absorber is calculated. It is found that the particle filling rate corresponding to the maximum particle energy dissipation rate is in agreement with the particle filling rate when the vibration acceleration of the pipeline decreases to the lowest, and the simulation results are in good agreement with the test results. Finally, the designed particle damper is installed on the hydraulic power supply pipeline for actual tests of vibration absorption. The vibration acceleration of the test pipe in three directions X,Y,Z before and after the installation of the damper is tested, and the results are compared and analyzed. It is found that the vibration level of hydraulic pipeline under pressure pulsation frequency is significantly restrained after the installation of particle damper. The experimental results fully suggest the effectiveness and practicability of the aircraft pipeline particle damper designed in this paper.