scholarly journals Energy dissipation prediction of particle dampers

2009 ◽  
Vol 319 (1-2) ◽  
pp. 91-118 ◽  
Author(s):  
C.X. Wong ◽  
M.C. Daniel ◽  
J.A. Rongong
2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Niklas Meyer ◽  
Robert Seifried

AbstractParticle damping is a promising damping technique for a variety of technical applications. However, their non-linear behavior and multitude of influence parameters, hinder currently its wide practical use. So far, most researchers focus either on determining the energy dissipation inside the damper or on the overall damping behavior when coupled to a structure. Indeed, currently almost no knowledge exchange between both approaches occurs. Here, a bridge is build to combine both techniques for systems under forced vibrations by coupling the energy dissipation field and effective particle mass field of a particle damper with a reduced model of a vibrating structure. Thus, the overall damping of the structure is estimated very quickly. This combination of both techniques is essential for an overall efficient dimensioning process and also provides a deeper understanding of the dynamical processes. The accuracy of the proposed coupling method is demonstrated via a simple application example. Hereby, the energy dissipation and effective mass of the particle damper are analyzed for a large excitation range first using a shaker setup. The particle damper exhibits multiple areas of different efficiency. The underlying structure is modeled using FEM and modal reduction techniques. By coupling both parts it is shown that multiple eigenmodes of the structure are highly damped using the particle damper. The damping prediction using the developed coupling procedure is validated via experiments of the overall structure with particle damper.


2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xiaowei Li ◽  
Yue Yang ◽  
Weixing Shi

Particle dampers are nonlinear vibration control devices. The surface property has a great influence on the performance of the particle damper, but it is difficult to be considered and analyzed. This paper firstly gives a view of how to establish a theoretic model of the particle damper. The dynamic equation and energy dissipation coefficient of collision are revised from the Hertz contact theory in the proposed theoretic model, considering the friction of particles. Then, a contrastive collision model relying on the finite element method is established to verify the reasonability of the theoretic model. The effects of different factors which will have an influence on the performance of the particle damper are discussed, and several conclusions on how to optimize the particle damper are proposed. Except for the aforementioned dynamic analysis, this paper also presents a particle damping index to evaluate the capability of energy dissipation of different materials, in order to facilitate the material selection in the practical design. Finally, an experiment is developed to verify the character of the collision and energy dissipation. The feasibility of the proposed method to estimate the surface property of different particles is validated by the free vibration experiment.


Author(s):  
Niklas Meyer ◽  
Robert Seifried

Abstract Particle dampers show a huge potential to reduce undesired vibrations in technical applications even under harsh environmental conditions. However, their energy dissipation depends on many effects on the micro- and macroscopic scale, which are not fully understood yet. This paper aims toward the development of design rules for particle dampers by looking at both scales. This shall shorten the design process for future applications. The energy dissipation and loss factor of different configurations are analyzed via the complex power for a large excitation range. Comparisons to discrete element simulations show a good qualitative agreement. These simulations give an insight into the process in the damper. For monodisperse systems, a direct correlation of the loss factor to the motion modes of the rheology behavior is shown. For well-known excitation conditions, simple design rules are derived. First investigations into polydisperse settings are made, showing a potential for a more robust damping behavior.


2016 ◽  
Vol 24 (4) ◽  
pp. 682-693
Author(s):  
Jianglong Fang ◽  
Xiaopeng Wang ◽  
Tianning Chen ◽  
Kai Zhang

To study the energy dissipation mechanism of nonobstructive particle dampers (NOPDs) and provide guidance to the application of NOPDs, the dense granular flow theory was introduced to establish a quantitative energy dissipation model for NOPDs. The convection movement of the particles under vibrational excitations was studied using the discrete element method, and the Prandtl mixing length theory was adopted to modify the constitution law of dense granular flows. The pressure of the granular flow was obtained by equivalenting the vibrational excitation to a body force acted on particles. Theoretical results showed that the energy dissipation rate of the NOPD was increased with the vibration intensity and decreased with the granular diameter. It also indicated that particles near the side wall and the bottom of the damper dissipated more energy than those particles in other regions. The theoretical model was verified by simulation and experimental result. The results may provide a new approach to studying the energy dissipation mechanism of NOPD and give some guidance to enhancing the damping performance of NOPD in engineering practices.


Author(s):  
Shilong Li ◽  
Jiong Tang

Particle damper is formed by granular particles enclosed in a container which is attached to or embedded in a vibrating structure. The energy dissipation mechanism of a particle damper is highly nonlinear, and derived from a combination of collision/impact and friction among particles and between particles and the enclosure. Meanwhile, the coupling between particle dampers and the host structure and among multiple dampers further increases the difficulty to analyze the particle damping performance. In this paper, a new coupling method is developed to integrate the continuous host system with multiple particle dampers to analyze the energy transfer between the host structure and the dampers. The discrete element method (DEM) is employed to describe and analyze the particle motion inside each damper, which accurately accounts for various energy dissipation mechanisms of the particle damping system. In order to enhance the computational efficiency, a Verlet table combined with LC method is also used to improve the contact detection since the long time simulation is needed to perform damping analysis under a wide range of frequencies. The damping effect under different arrangements of particle dampers on a clamped-free beam is analyzed, and the results indicate that the optimal positions of dampers not only rely on the mode shape of the system, but also are dependent upon the excitation level.


2012 ◽  
Vol 479-481 ◽  
pp. 1307-1309
Author(s):  
Zhao Wang Xia ◽  
Yuan Yuan Fang

The performance of particle damper is highly nonlinear whose energy dissipation is derived from a combination of mechanisms including plastic collisions, friction, and momentum transfer between particles. Particle damper can be applied in extreme temperature environments. In this paper, an investigation on particle damper is performed analytically and experimentally. A simulation algorithm and results of simulative studies aimed at understanding the effects of parameters of particle damper are presented. Parameters considered include damper geometry, particle material and particle size.


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