Simulation test of underwater vehicle shafting based on particle damping in longitudinal vibration suppression

Under the condition of simple harmonic excitation, a simulation test device of shafting longitudinal vibration suppression based on the particle damping was used to investigate the vibration reduction ratio of particle damping in a rotating condition. The acceleration variations of shafting simulation system for single- and multiple-cavity particle dampers were explored, and the parameters influencing the vibration reduction ratio of the system, such as material, size and filling ratio of particle, cavity number, rotating speed, frequency, and amplitude of excitation, were examined. Research results show that when there are multiple particles in a single cavity, the vibration reduction ratio of a system filled with copper, steel, and rubber-coated steel particles is between 7.83% and 8.91%, and that of a system filled with rubber particles is close to zero. This indicates that copper, steel, and rubber-coated steel particles have an obvious suppression effect, and the higher the material density and damping ratio of the particles, the better the damping effect. When the particle mass filling ratio is 15%, the maximum vibration reduction ratio of the system is 13.77%. However, when the mass filling ratio exceeds 15%, the vibration damping ratio of the system decreases. Therefore, the mass filling ratio should be controlled at approximately 15% according to the actual situation. The influences of particle size, rotating speed, excitation frequency, and displacement amplitude on the vibration reduction ratio of the system are 1.76%-8.68%, 6.77%-12.50%, 4.41%-10.12%, and 2.19%-7.05%, respectively. Under a multicavity and multiparticle condition, when the total mass filling ratio of the particles and the rotating speed are constant, the cavity number has a significant impact on the vibration reduction ratio of the system. When the cavity number is 3, the best vibration reduction ratio of the system is 22.5% under a rotating speed of 100 r·min^-1 and a mass filling ratio of 25%. Under multicavity and multiple particle sizes, when the total mass filling ratio is 10% and the rotating speed is 50-150 r·min^-1, the vibration reduction ratio of the system fluctuates little, with an average of 14.18%. This shows that the combined multicavity and multiple-particle-size system is not very sensitive to the rotating speed, and it has a better vibration reduction effect. As a result, the range of the rotating speed can be widened. 14 tabs, 18 figs, 30 refs.