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Damping and elastic properties of binary powder mixtures
Published in Y. Kishino, Powders and Grains 2001, 2020
T. Yanagida, A.J. Matchett, J.M. Coulthard
Particulate systems subject to vibration behave as better energy absorbers than continuous materials. The damping characteristics have been applied as a damping technique to absorb vibration energy of mechanical vibration. Panossian suggested a “Non-Obstructive Particle Damping Technique” using this damping effect, indicating that the technique is a very effective vibration damping methodology that has potential applications in all areas of structure vibration (Panossian 1992). For a wide applicability of this technology, it is desired to control adequately the damping effect for the required frequency range. Use of mixtures enables control of the frequency range of damping because it is possible to control the properties of mixtures by changing the constituted material and the mixing fraction etc. In order to produce the required mixtures, an understanding of both the damping and elastic properties of mixtures is essential.
Dynamic investigation and experimental validation of a gear transmission system with damping particles
Published in Mechanics Based Design of Structures and Machines, 2023
Yun-Chi Chung, Achmad Arifin, Yu-Ren Wu, Chia-Yuan Wang
Particle damping technology was implemented for rotating bodies (Dragomir et al. 2012), in which the friction and collision generated during the motion of the particles were applied to achieve energy dissipation by mounting the structure with damping particles on the rotating shaft. Another investigation was performed by adding damping particles into the gear cavity and analyzing the relationship between particles and energy dissipation in distinct operating conditions. The results revealed that the friction coefficient had a substantial impact on the damping particles, and the motion behavior of the damping particles at high and low speeds exhibited diverse trends (Xiao, Huang, et al. 2016; Xiao et al. 2017). Therefore, in this study, all damping particles were considered independent units in order to further analyze damping particles’ motion, and the discrete element method (DEM) was used to determine the motion behavior of each damping particle. DEM was first proposed to treat discontinuous material as multiple connected discrete spheres (Cundall and Strack 1979). The DEM technique was also applied in a gear transmission system to establish MBD-DEM coupling analysis (Xiao, Huang, et al. 2016; Xiao et al. 2017). The results showed that the particle filling ratio, material, and other particle parameters had a distinct effect on the vibration reduction impact of particles. Selecting the most suitable particle material can more effectively reduce vibration in gearing systems. Consequently, it provided an essential basis for applying particle selection in centrifugal fields. A two-way coupled dynamic model of multi-body dynamics (MBD) and DEM modeling and experimental validation for the dynamic response of mechanisms containing damping particles, particularly the motion behavior of damping particles in gears were further described (Chung and Wu 2019; Wu, Chung, and Wang 2021). In that study, the particles had the optimum particle size to ensure that the particle grade did not influence the system vibration response. Accordingly, an equivalent mass was determined as an additional case to provide an important reference for selecting particle parameters in this study.