Abstract: To solve the problem of pipeline vibration, a kind of built-in grid particle damper is proposed to improve the traditional particle damper's poor damping effect under large excitation. The vibration characteristics of the pipeline are analyzed based on the finite element method. The second and third order natural modal frequencies exist in the adjustable speed range of the fan, and the control process of the pipeline vibration is simulated by multi-body dynamics and discrete element joint simulation. The reliability of the simulation results is verified by the experimental platform of pipeline vibration control. The results show that when the particle diameter is 6 mm, the built-in grid particle damper has better damping effect. When filled with 6 mm stainless steel, zirconia, and aluminum alloy particles respectively, stainless steel particles are found to exhibit the optimal damping effect. When the particle filling rate is 90%, the built-in grid particle damper can reduce the vibration of the pipeline at the second and third mode frequencies by 53% and 54%, respectively. The energy dissipation mechanism of the internal grid damper and the non-grid particle damper is compared. It is found that the particle velocity vector in the internal grid damper is more regular, and the kinetic energy, energy consumption and collision times of the particles are more frequent. It is verified that the internal grid particle damper has better damping effect at high excitation level. In order to exclude the influence of the mass of the damper itself on the vibration reduction effect, the equal mass control is adopted to verify the effectiveness of the particle vibration reduction effect.

Key words: pipeline vibration, particle damper, built-in grid, energy dissipation, discrete element method