Universal response of optimal granular damping devices

Sánchez, M.; Rosenthal, Gustavo; Pugnaloni, Luis A.

doi:10.1016/j.jsv.2012.05.001

Cited by 66 publications

(38 citation statements)

References 23 publications

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“…Of particular relevance to our current investigation is the work of Sánchez et al [31] which shows that, under the right conditions (namely a large particle number, N, and a high particle density, η), the resonant response of a granular damper is effectively independent of the material properties possessed by the individual particles of which it is formed. It is hypothesized that this universal response occurs due to the inelastic collapse [32,33] exhibited by a granular system under the aforementioned bed conditions, meaning that the bed will possess effectively zero elasticity, irrespective of the specific restitution (ε) and frictional (μ) coefficients of the particles involved (at least so long as μ > 0 and/or ε < 1).…”

Section: Introductionmentioning

confidence: 92%

Resonance effects on the dynamics of dense granular beds: achieving optimal energy transfer in vibrated granular systems

et al. 2015

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Using a combination of experimental techniques and discrete particle method simulations, we investigate the resonant behaviour of a dense, vibrated granular system. We demonstrate that a bed of particles driven by a vibrating plate may exhibit marked differences in its internal energy dependent on the specific frequency at which it is driven, even if the energy corresponding to the oscillations driving the system is held constant and the acceleration provided by the base remains consistently significantly higher than the gravitational acceleration, g. We show that these differences in the efficiency of energy transfer to the granular system can be explained by the existence of resonances between the bed's bulk motion and that of the oscillating plate driving the system. We systematically study the dependency of the observed resonant behaviour on the system's main, controllable parameters and, based on the results obtained, propose a simple empirical model capable of determining, for a given system, the points in parameter space for which optimal energy transfer may be achieved. been demonstrated [15] that, for relatively shallow, strongly fluidized systems, this assumption does not necessarily hold true; rather, the dynamic properties of a vertically vibrated granulate are additionally sensitive to the specific combinations of f and A used to produce a given v, S or Γ. In other words, two systems vibrated with the same input energy achieved using two differing combinations of f and A may exhibit strongly disparate properties. Similarly, it is found that two systems driven with markedly different S and/or Γ values may possess near-identical internal energies, in direct contradiction of the monotonic relations one might expect.Specifically, for dilute systems such as those described in [15], it was found that an increase in A at fixed S resulted in an increase in the total energy possessed by the excited granulate. This greater energy transfer from the vibrating system to the granular bed at large driving amplitudes was attributed to the observed increase in the particle-base collision rate with increasing A. In other words, the lack of a simple, monotonic relationship between a granulate's kinetic and/or potential energy and any of the individual parameters v S , or Γ can be explained by the fact that such parameters do not provide sufficient information regarding certain key variables, in this case the particle-base collision rate within the system. As such, in order to accurately characterize the steady-state of such a system, one requires a pair of driving variables, f and A-in addition, of course, to a knowledge of the system's depth and dissipative properties.Recent works by Pugnaloni et al [16,17] have similarly challenged the assumption that a system's steady state may be adequately defined by a single parameter, in this instance for the case of a granular bed excited by a series of discrete taps, as opposed to continuous vibration. Specifically, it was, until recently, a generally held belief [18,19] that ...

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Section: Introductionmentioning

confidence: 92%

Resonance effects on the dynamics of dense granular beds: achieving optimal energy transfer in vibrated granular systems

et al. 2015

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“…Discrete element models have been comprehensively applied to particle dampers and might represent a good alternative for modelling. 12,13,[26][27][28][29][30] The effectiveness of EPDs is greatly improved when the working frequency is tuned to a vibration mode of a plate and when the dampers are strategically located at points at which high displacement occurs. In particular, the three EPDs in this study, tuned to the vibration mode [2 0] of a steel plate, were applied.…”

Section: Discussionmentioning

confidence: 99%

High Damping Characteristics of an Elastomer Particle Damper

Bustamante¹,

Gerges²,

Vergara³

et al. 2016

IJAV

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Research testing has led to the development of an Elastomer Particle Damper (EPD), which can add considerable damping to a structure by directing the vibration to a set of interacting elastomer particles through a rigid connection. This vibration treatment presents highly nonlinear behavior that is strongly dependent on both the vibration amplitude and frequency. Curves of damping loss factor (DLF) of an EPD system with vertical motion as a function of frequency and acceleration are reported herein. The results show that the elastomer particle damper has two distinct damping regions. The first region is related to the fluidization state of the particles, as described in the literature, obtained when the damper is subjected to vertical acceleration close to 1 g and frequencies below 50 Hz. The second region presents high values of DLF to acceleration values lower than 1 g, and the frequency range is dependent upon the stiffness of the particles. A high degree of effectiveness is achieved when the working frequency of the elastomer particle dampers is tuned to a natural frequency of a plate and when they are strategically located at points having large displacement. The performance of EPDs was compared with that of a commercial constrained layer damping installed in an aircraft floor panel. The EPDs achieved an acceleration level attenuation in the aircraft floor panel similar to that of the commercial constrained layer damping system.

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“…When tiny particles were used (300 μm), different patterns appeared depending on the vibration frequency f, for instance, stable oscillons and surface waves similar to those observed in vibrated granular beds [15][16][17][18][19]. The above grain size dependence reveals, as in the case of granular dampers [20][21][22][23][24][25], the relevance of the main dissipation mechanism: interparticle collisions for large particles and friction as the particle size decreases.Experimental setup.-A transparent ping-pong ball (coefficient of restitution ϵ c ≈ 0.91 AE 0.02, mass m c ¼ 1.9 AE 0.1 g, and inner or outer diameter D c ¼ 3.75=3.80 AE 0.02 cm) was partially filled with liquid or grains and placed on a steel plate (mass ¼ 240 g) subjected to vertical oscillations SðtÞ ¼ A sinðωtÞ; here, A is the vibration amplitude and ω ¼ 2πf. To ensure that the ball was bouncing, we used a dimensionless acceleration Γ ¼ Aω 2 =g > 1.…”

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confidence: 81%

Dynamics of a Grain-Filled Ball on a Vibrating Plate

2014

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We study experimentally how the bouncing dynamics of a hollow ball on a vibrating plate is modified when it is partially filled with liquid or grains. Whereas empty and liquid-filled balls display a dominant chaotic dynamics, a ball with grains exhibits a rich variety of stationary states, determined by the grain size and filling volume. In the collisional regime, i.e., when the energy injected to the system is mainly dissipated by interparticle collisions, an unexpected period-1 orbit appears independently of the vibration conditions, over a wide range. This is a self-regulated state driven by the formation and collapse of a granular gas within the ball during one cycle. In the frictional regime (dissipation dominated by friction), the grains move collectively and generate different patterns and steady modes: oscillons, waves, period doubling, etc. From a phase diagram and a geometrical analysis, we deduce that these modes are the result of a coupling (synchronization) between the vibrating plate frequency and the trajectory followed by the particles inside the cavity. A bouncing ball (BB) on a vibrated plate is a fundamental system used as a model in different physical and engineering problems [1]; for instance, it has been used to describe cosmic-ray particles in astrophysics [2], the dynamic stability in human performance [3], and the cantilever motion in atomic force microscopy [4]. The BB dynamics displays a period doubling route to chaos also found in biological, hydrodynamic, optical, and chemical systems [5]. More complex objects such as dimers [6], trimers [7], bouncing droplets [8], and quantum bouncers [9] also show nonlinear behaviors: bifurcations, rotations, etc. Dimers and trimers exhibit self-propulsion, providing models to study collective motions, such as fish schools [10], flocks [11], and bacteria colonies [12]. Clearly, the study of bouncing objects has been relevant to the description of a large variety of nonlinear behaviors.This Letter explores the bouncing dynamics of a hollow sphere partially filled with grains. We aim to understand how the classical BB dynamics (widely studied in the literature [1,5,13,14]) is affected by the fast energy dissipation typical of granular materials. We compared the dynamics of an empty, a liquid-filled, and a grain-filled sphere. The former two cases exhibit chaotic behaviors while the sphere with grains bounces primarily in steady states. Of particular interest was the observation of a period-1 orbit independent of the vibration conditions in a broad range. This state was observed at low filling ratios V f (< 12%) and using large beads (diameter d ¼ 2 mm). When tiny particles were used (300 μm), different patterns appeared depending on the vibration frequency f, for instance, stable oscillons and surface waves similar to those observed in vibrated granular beds [15][16][17][18][19]. The above grain size dependence reveals, as in the case of granular dampers [20][21][22][23][24][25], the relevance of the main dissipation mechanism: interparticle collisio...

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Universal response of optimal granular damping devices

Cited by 66 publications

References 23 publications

Resonance effects on the dynamics of dense granular beds: achieving optimal energy transfer in vibrated granular systems

Resonance effects on the dynamics of dense granular beds: achieving optimal energy transfer in vibrated granular systems

High Damping Characteristics of an Elastomer Particle Damper

Dynamics of a Grain-Filled Ball on a Vibrating Plate

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