• Title/Summary/Keyword: particle damper

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Characteristics of Energy Dissipation in Vibration Absorbing Nano-Damper According to the Architecture of Silica Particle (세라믹 분말의 입자구조에 따른 나노 진동 흡수장치의 에너지 소산 효율 특성에 대한 연구)

  • Moon, Byung-Young;Kim, Heung-Seob
    • Korean Journal of Materials Research
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    • v.13 no.3
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    • pp.144-149
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    • 2003
  • This study shows an experimental investigation of a reversible nano colloidal damper, which is statically loaded. The porous matrix is composed from silica gel (labyrinth or central-cavity architecture), coated by organo-silicones substances, in order to achieve a hydrophobic surface. Water is considered as associated lyophobic liquid. Reversible colloidal damper static test rig and the measuring technique of the static hysteresis are described. Influence of the pore and particle diameters, particle architecture and length of the grafted molecule upon the reversible colloidal damper hysteresis is investigated, for distinctive types and mixtures of porous matrices. Variation of the reversible colloidal damper dissipated energy and efficiency with temperature, pressure, is illustrated. As a result, he proposed nano damper is effective one, which can be replaced the conventional damper.

An experimental study of vibration control of wind-excited high-rise buildings using particle tuned mass dampers

  • Lu, Zheng;Wang, Dianchao;Masri, Sami F.;Lu, Xilin
    • Smart Structures and Systems
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    • v.18 no.1
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    • pp.93-115
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    • 2016
  • A particle tuned mass damper (PTMD) system is the combination of a traditional tuned mass damper (TMD) and a particle damper (PD). This paper presents the results of an experimental and analytical study of the damping performance of a PTMD attached to the top of a benchmark model under wind load excitation. The length ratio of the test model is 1:200. The vibration reduction laws of the system were explored by changing some system parameters (including the particle material, total auxiliary mass ratio, the mass ratio between container and particles, the suspending length, and wind velocity). An appropriate analytical solution based on the concept of an equivalent single-unit impact damper is presented. Comparison between the experimental and analytical results shows that, with the proper use of the equivalent method, reasonably accurate estimates of the dynamic response of a primary system under wind load excitation can be obtained. The experimental and simulation results show the robustness of the new damper and indicate that the damping performance can be improved by controlling the particle density, increasing the amount of particles, and aggravating the impact of particles etc.

Studies on vibration control effects of a semi-active impact damper for seismically excited nonlinear building

  • Lu, Zheng;Zhang, Hengrui;Masri, Sami F.
    • Smart Structures and Systems
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    • v.24 no.1
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    • pp.95-110
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    • 2019
  • The semi-active impact damper (SAID) is proposed to improve the damping efficiency of traditional passive impact dampers. In order to investigate its damping mechanism and vibration control effects on realistic engineering structures, a 20-story nonlinear benchmark building is used as the main structure. The studies on system parameters, including the mass ratio, damping ratio, rigid coefficient, and the intensity of excitation are carried out, and their effects both on linear and nonlinear indexes are evaluated. The damping mechanism is herein further investigated and some suggestions for the design in high-rise buildings are also proposed. To validate the superiority of SAID, an optimal passive particle impact damper ($PID_{opt}$) is also investigated as a control group, in which the parameters of the SAID remain the same, and the optimal parameters of the $PID_{opt}$ are designed by differential evolution algorithm based on a reduced-order model. The numerical simulation shows that the SAID has better control effects than that of the optimized passive particle impact damper, not only for linear indexes (e.g., root mean square response), but also for nonlinear indexes (e.g., component energy consumption and hinge joint curvature).

Vibration control of offshore wind turbine using RSM and PSO-optimized Stockbridge damper under the earthquakes

  • Islam, Mohammad S.;Do, Jeongyun;Kim, Dookie
    • Smart Structures and Systems
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    • v.21 no.2
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    • pp.207-223
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    • 2018
  • In this inquisition, a passive damper namely Stockbridge Damper (SBD) has been introduced to the field of vibration control of Offshore Wind Turbine (OWT) to reduce the earthquake excitations. The dynamic responses of the structure have been analyzed for three recorded earthquakes and the responses have been assessed. To find an optimum SBD, the parameters of damper have been optimized using Response Surface Methodology (RSM) based on Box-Behnken Design (BBD) and Particle Swarm Optimization (PSO). The influence of the design variables of SBD such as the diameter of messenger cable, the length of messenger cable and logarithmic decrement of the damping has been investigated through response variables such as maximum displacement, RMS displacement and frequency amplitude of structure under an artificially generated white noise. After that, the structure with optimized and non-optimized damper has been analyzed with under the same earthquakes. Moreover, the comparative results show that the structure with optimized damper is 11.78%, 18.71%, 11.6% and 7.77%, 7.01%, 10.23% more effective than the structure with non-optimized damper with respect to the displacement and frequency response under the earthquakes. The results show that the SBD can obviously affect the characteristics of the vibration of the OWT and RSM based on BBD and PSO approach can provide an optimum damper.

Energy dissipation by particle sloshing in a rolling cylindrical vessel (분체슬로싱 현상에 의한 원통형 용기에서의 에너지 소실)

  • Lee, Soo-Hyuk;Heo, Sung-Mo;Cho, Hye-Min;Son, Hyunsung;Jeong, Seong-Min;Park, Junyoung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.3
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    • pp.62-68
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    • 2010
  • In the engineering field, sloshing in rolling vessel is a hot issue because of the connection with ship stability problem. The sloshing phenomena also can be utilized in the field of structure or facility vibration damper. This paper explores the possibility which sloshing of multi-particles can be used to dissipate energy in a rolling container. This energy dissipation can be utilized to the application of rotating damper. Some of the parameters expected to dissipates energy, such as vessel size, particle size, mass fraction and ramp height, have been experimentally and theoretically studied.

Performance Investigation of a Continuously Variable ER Damper for Passenger Vehicles (승용차용 연속가변 ER댐퍼의 성능연구)

  • Kim, K.S.;Chang, E.;Choi, S.B.;Cheong, C.C.;Suh, M.S.;Yeo, M.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.6
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    • pp.69-77
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    • 1995
  • This paper presents performance investigation of a continuously variable ER(Electro-Rheological) damper for passenger vehicles. A dynamic model of the damper is formulated by incorporating electric field-dependent Bingham properties of the ER fluid. The Bingham properties are experimentally obtained through Couette type electroviscous measurement with respect to two different particle concentrations. The governing equation of the hydraulic model treating three components of fluid resistances;electrode duct flow, check valve flow and piston gap flow, is achieved via the bond graph method. A prototype ER damper is then designed and manufactured on the basis of parameter analysis. The damping forces of the system are experimentally evaluated by changing the intensity of the electric field, the particle concentration and the electrode gap.

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Effect of Water Volume and Relaxation Time in the Design of Nano Shock Absorbing Damper Using Silica Particle (실리카 분말을 이용한 나노 충격완화 장치의 설계에서 작동 유체 영향과 복원 시간에 대한 연구)

  • 문병영;김병수
    • Journal of the Korean Ceramic Society
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    • v.40 no.3
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    • pp.286-292
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    • 2003
  • In this study, new shock absorbing system was proposed using silica gel particles according to the nano-technology. For the design and real application of the proposed damper, an experimental investigations are carried out using colloidal damper, which is statically loaded. The porous matrix is composed from silica gel(labyrinth architecture), coated by organo-silicones substances, in order to achieve a hydrophobic surface. Water is considered as associated lyophobic liquid. Reversible colloidal damper static test rig and the measuring technique of the static hysteresis were described. Iufluence of the water volume and particle diameters upon the reversible colloidal damper hysteresis was investigated. Also, influence of the relaxation time on the hysteresis of the damper was investigated. As a result, the proposed new shock absorbing damper is proved as an effective one, which can be replaced for the conventional hydraulic damper.

Performance Evaluation of Small Dampers Using SMG Fluid (SMG 유체를 이용한 소형댐퍼의 성능평가)

  • Heo, Gwang Hee;Jeon, Seung Gon;Seo, Sang Gu;Kim, Dae Hyeok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.4
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    • pp.211-219
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    • 2019
  • In this study, SMG(Smart Material with Grease) was developed, which was improved the precipitation minute particle in grease during long term standstill. Also, small-sized cylinder damper equipped with an electromagnet in a piston was developed for using a performance evaluation of the damper with SMG and the dynamic load test, and damping force using Power model and Bingham model was derived in order to compare to the result of that of the damper. The data obtained from the dynamic load test were analyzed and plotted, and then a dynamic range was calculated to evaluate the usability of the damper with SMG. The performance of the damper with SMG was compared to the damping forse derived from the Power and Bingham model. The result of this evaluation shown that the usability of SMG damper was demonstrated by this test as a semi-active controlling equipment of small-sized damper.

Vibration control performance of particle tuned mass inerter system

  • Zheng Lu;Deyu Yan;Chaojie Zhou;Ruifu Zhang
    • Structural Engineering and Mechanics
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    • v.89 no.4
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    • pp.383-397
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    • 2024
  • To improve the vibration control performance and applicability of traditional particle tuned mass damper (PTMD) and realize the significant characteristic of lightweight design, this study proposes a novel particle tuned mass inerter system (PTMIS) by introducing inerter system (IS) to the PTMD. In the study, the motion equation of single degree of freedom (SDOF) structure attached with PTMIS is established first, then the variation law of the system's vibration reduction performance (VRP) is discussed through parameter analysis, and it is compared with the PTMD to analyze its VRP advantages. Finally, its vibration reduction (VR) mechanism from the perspective of core control force and energy analysis is explored, and its cavity relative displacement from the application perspective is analyzed. The results show that the PTMIS can remarkably improve the vibration control effectiveness of the PTMD. The reason is that the inerter can store energy and transfer the energy to the cavity and particles, which further stimulates the interaction between the two parts, thereby improving the nonlinear energy consumption effectiveness. Also, the IS can amplify the damping element's energy dissipation efficiency. In addition, the PTMIS can effectively reduce the working stroke of the PTMD, and through the analysis of the lightweight characteristics of the PTMIS, it is found that its lightweight advantage can reach nearly 100%.

Characteristics of Energy Dissipation in Nano Shock Suspension System Using Silica Gel (세라믹 분말을 이용한 나노 충격 완화 장치의 에너지 소산 효율 특성에 대한 연구)

  • 문병영;정성원
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.3
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    • pp.17-22
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    • 2003
  • This paper presents an experimental investigation of a reversible colloidal seismic damper, which is statically loaded, The porous matrix is composed from silica gel (labyrinth or central-cavity architecture), coated by organo-silicones substances, in order to achieve a hydrophobic surface. Water is considered as associated lyophobic liquid. Reversible colloidal damper static test rig and the measuring technique of the static hysteresis are described. Influence of the pare and particle diameters, particle architecture and length of the grafted molecule upon the reversible colloidal damper hysteresis is investigated, for distinctive types and mixtures of porous matrices, Variation of the reversible colloidal damper dissipated energy and efficiency with temperature, pressure, is illustrated.