Polymeric particle dampers under steady-state vertical vibrations

Darabi, Babak; Rongong, J.A.

doi:10.1016/j.jsv.2012.03.005

Cited by 31 publications

(20 citation statements)

References 26 publications

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“…A sketch of such Granular damping element (GDE) is shown Fig.1, whereas Fig.2 schematically presents its working principle. Described GDE elements differ from the similar elements, devices and patents 30-33 that use sand 34,35 , granulated polymers [36][37][38][39] or metals [40][41][42][43][44][45] for enhanced damping, since in our case enhanced damping is not only the result of friction between particles but also result of changed material properties.…”

Section: A Granular Damping Elementsmentioning

confidence: 91%

Viscoelasticity of new generation thermoplastic polyurethane vibration isolators

et al. 2017

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This paper presents the analysis of pressure dependence of three thermoplastic polyurethane (TPU) materials on vibration isolation. The three TPU Elastollan R materials are: 1190A, 1175A and 1195D. Aim of this investigation was to analyze how much the performance of isolation can be enhanced using patented Dissipative bulk and granular systems technology. The technology uses granular polymeric materials to enhance materials properties (without changing its chemical or molecular composition) by exposing them to 'self-pressurization', which shifts material energy absorption maxima towards lower frequencies, to match the excitation frequency of dynamic loading to which a mechanical system is exposed. Relaxation experiments on materials were performed at different isobaric and isothermal states to construct mastercurves, the time-temperature-pressure interrelation was modeled using the Fillers-Moonan-Tschoegl model. Dynamic material functions, related to isolation stiffness and energy absorption, were determined with the Schwarzl approximation. An increase of stiffness and energy absorption at selected hydrostatic pressure, compared to its stiffness and energy absorption at ambient conditions, is represented with κ k (p, ω), defining the increase of stiffness and κ d (p, ω), defining the increase of energy absorption. The study showed that close to the glassy state, moduli of 1190A and 1195D is about 6-9 times higher compared to 1175A, whereas, their properties at ambient conditions are for all practical purposes the same. TPU 1190A turns out to be most sensitive to pressure: at 300M P a its properties are shifted for 5.5 decades, while for 1195D and 1175A this shift is only 3.5 and 1.5 decades, respectively. In conclusion, the stiffness and energy absorption of isolation may be increased with pressure for about 100 times for 1190A and 1195D, and for about 10 times for 1175A. a) Dedicated to dr. David Binding for his contributions to the field of Rheology.

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Section: A Granular Damping Elementsmentioning

confidence: 91%

Viscoelasticity of new generation thermoplastic polyurethane vibration isolators

et al. 2017

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“…This type of variant mainly includes the buffered impact damper, [61] the fine particle impact damper, [62] the polymeric particle damper, [63,64] the elastomer particle damper, [65] the soft hollow particle damper, [66] the metal swarf damper, [67] and the metallic wires particle damper. [68][69][70] Li et al [61] covered the inner wall of the particle damper with thin rubber material, which formed the buffered impact damper.…”

Section: The Materials Improved Type Of Particle Dampersmentioning

confidence: 99%

Particle impact dampers: Past, present, and future

Wang

Masri

Lü

2017

Struct Control Health Monit

201

105

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Particle damping, an effective passive vibration control technology, is developing dramatically at the present stage, especially in the aerospace and machinery fields. The aim of this paper is to provide an overview of particle damping technology, beginning with its basic concept, developmental history, and research status all over the world. Furthermore, various interpretations of the underlying damping mechanism are introduced and discussed in detail. The theoretical analysis and numerical simulation, together with their pros and cons are systematically expounded, in which a discrete element method of simulating a multi-degree-of-freedom structure with a particle damper system is illustrated. Moreover, on the basis of previous studies, a simplified method to analyze the complicated nonlinear particle damping is proposed, in which all particles are modeled as a single mass, thereby simplifying its use by practicing engineers. In order to broaden the applicability of particle dampers, it is necessary to implement the coupled algorithm of finite element method and discrete element method. In addition, the characteristics of experimental studies on particle damping are also summarized. Finally, the application of particle damping technology in the aerospace field, machinery field, lifeline engineering, and civil engineering is reviewed at length. As a new trend in structural vibration control, the application of particle damping in civil engineering is just at the beginning. The advantages and potential applications are demonstrated, whereas the difficulties and deficiencies in the present studies are also discussed. The paper concludes by suggesting future developments involving semi-active approaches that can enhance the effectiveness of particle dampers when used in conjunction with structures subjected to nonstationary excitation, such as earthquakes and similar nonstationary random excitations. KEYWORDS discrete element method, impact damping, nonlinear energy sink, particle damping, passive control, semiactive control | INTRODUCTIONParticle damping technology is a form of an auxiliary-mass type vibration damper, wherein multiple metal, tungsten carbide, ceramic or other types of small particles are placed within the cavities of the vibrating structure, or the enclosures attached to the vibrating structure in order to mitigate the response of the primary structure. [1,2] As the primary structure vibrates, kinetic energy is significantly absorbed through the combined effects of particle-to-particle and particle-to-wall inelastic collisions and frictional losses, producing considerable damping to the primary structure. [3][4][5][6] Particle damping technology has been widely Received: 23 February 2017 Revised: used due to its conceptual simplicity, moderate cost, good durability, and temperature insensitivity. Provided that the operating temperature is below the particles' metal melting point, it could maintain normal operation. Furthermore, material such as tungsten powder can withstand the high temp...

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“…In order to verify the energy dissipation model proposed in this paper, the dissipation power of the NOPD was tested using the test rig shown in Figure 7. The dissipation power was measured using the Fourierbased power flow method Wong et al (2009) and Darabi and Rongong (2012) used in their works. Initially, three different sets of experiments were conducted.…”

Section: Experiments Verificationmentioning

confidence: 99%

Research on the energy dissipation mechanism of nonobstructive particle dampers based on the dense granular flow theory

Fang

Wang

Chen

et al. 2016

Journal of Vibration and Control

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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.

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Polymeric particle dampers under steady-state vertical vibrations

Cited by 31 publications

References 26 publications

Viscoelasticity of new generation thermoplastic polyurethane vibration isolators

Viscoelasticity of new generation thermoplastic polyurethane vibration isolators

Particle impact dampers: Past, present, and future

Research on the energy dissipation mechanism of nonobstructive particle dampers based on the dense granular flow theory

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