| 摘要(英) |
Why do sound experts always fill the loudspeaker stands with steel beads or quartz sand to improve the sound quality of the loudspeaker? The mechanism of this interesting physical phenomenon has not yet been thoroughly studied and clarified. In this study, two-way Couple DEM-FEM Approach was employed to model the dynamic response of commercially available loudspeaker stands equipped with damping particles, and the corresponding physical experiments were performed to validate the proposed numerical model. The effect of particle properties, such as the inter-particle friction coefficient, the particle-wall friction coefficient, the inter-particle restitution coefficient, and the Young′s modulus of particles, on the dynamic response of the loudspeaker stands was further explored, and the outcome can guide the audio industry to select the appropriate particles. This study used damping factors, friction energy dissipation efficiency, collision energy dissipation efficiency and total energy dissipation efficiency to quantify the system′s vibration reduction effect, and innovatively introduced particle transport properties (including local average velocity, fluctuation velocity distribution and granular temperature) to explore the performance of vibration reduction effect. The main findings are highlighted below: (1) As the external force amplitude increases, the dominant energy dissipation mechanism transforms from the damping dissipation mechanism to the friction dissipation mechanism; (2) The particle properties affect the damping effect. Among them, the Young′s modulus of the particles exhibits the most significant effect. In a certain range of Young’s modulus, a tuned mass damper occurs inside the granular solid, leading to the best damping effect; (3) The condition with smaller friction coefficients and larger Young’s modulus and restitution coefficients provides higher friction energy dissipation efficiency. As the external force amplitude increases, the friction dissipation efficiency increases while the collision dissipation efficiency decreases. The resultant effect from both mechanisms causes the total energy dissipation efficiency to decrease. (4) Both simulations and experiments confirmed that filling particles into the loudspeaker stands can attenuate vibrations for the frequencies studied here, especially at frequencies above 1kHz, and change the frequency response of the sound above 1kHz. (5) Filling particles with a larger Young′s modulus can increase the damping effect at frequencies above 1kHz, but decrease the damping effect at frequencies below 1kHz. (6) The damping effect has a significant correlation with the local average vertical velocity, fluctuation velocity distribution and granular temperature of particles. |
| 參考文獻 |
參考文獻
[1] A.R. Timmins, R.E. Heuser, S. FlightCenter, A study of first-day space malfunctions, NASA (1971).
[2] H.V. Panossian, Structural damping enhancement via non-obstructive particle damping technique, J. Vib. Acoust. 114 (1992) 101–105.
[3] P. Veeramuthuvel, K. Shankar, K.K. Sairajan, Application of particle damper on electronic packages for spacecraft, Acta Astronaut. 127 (2016) 260–270.
[4] M. Heckel, A. Sack, J.E. Kollmer, T. Pöschel, Granular dampers for the reduction of vibrations of an oscillatory saw, Phys. Stat. Mech. Its Appl. 391 (2012) 4442–4447.
[5] Z. Xu, M.Y. Wang, T. Chen, A particle damper for vibration and noise reduction, J. Sound Vib. 270 (2004) 1033–1040.
[6] Y. Liu, A. Sanchez, M. Zogg, P. Ermanni, A comparative experimental study on structural and interface damping approaches for vibration suppression purposes, in: M.N. Ghasemi-Nejhad (Ed.), San Diego, California, USA, 2010: p. 764335.
[7] P. Bartkowski, R. Zalewski, A concept of smart multiaxial impact damper made of vacuum packed particles, MATEC Web Conf. 157 (2018) 05001.
[8] A. Papalou, S.F. Masri, An experimental investigation of particle dampers under harmonic excitation, J. Vib. Control. 4 (1998) 361–379.
[9] R.D. Friend, V.K. Kinra, Particle impact damping, J. Sound Vib. 233 (2000) 93–118.
[10] Wu C., Prediction on Vibration response of cantilever particle-damping beam based on two-phase flow theory of gas-particle, J. Mech. Eng. 49 (2013) 53.
[11] Z. Xu, M.Y. Wang, T. Chen, Particle damping for passive vibration suppression: numerical modelling and experimental investigation, J. Sound Vib. 279 (2005) 1097–1120.
[12] J. Rongong, G. Tomlinson, Amplitude dependent behaviour in the application of particle dampers to vibrating structures, in: 46th AIAA/ASME/ASCE/AHS/ASC Struct. Struct. Dyn. Mater. Conf., American Institute of Aeronautics and Astronautics, Austin, Texas, 2005.
[13] J.F. Chen, J.M. Rotter, J.Y. Ooi, A review of numerical prediction methods for silo wall pressures, Adv. Struct. Eng. 2 (1999) 119–135.
[14] Q.J. Zheng, A.B. Yu, Finite element investigation of the flow and stress patterns in conical hopper during discharge, Chem. Eng. Sci. 129 (2015) 49–57.
[15] P.A. Cundall, O.D.L. Strack, A discrete numerical model for granular assemblies, Géotechnique. 29 (1979) 47–65.
[16] C.J. Coetzee, D.N.J. Els, Calibration of discrete element parameters and the modelling of silo discharge and bucket filling, Comput. Electron. Agric. 65 (2009) 198–212.
[17] X. Fang, J. Tang, Granular damping in forced vibration: qualitative and quantitative Analyses, J. Vib. Acoust. 128 (2006) 489–500.
[18] M. Saeki, Impact damping with granular materials in a horizontally vibrating system, J. Sound Vib. 251 (2002) 153–161.
[19] W. Xiao, J. Li, T. Pan, X. Zhang, Y. Huang, Investigation into the influence of particles’ friction coefficient on vibration suppression in gear transmission, Mech. Mach. Theory. 108 (2017) 217–230.
[20] C.X. Wong, M.C. Daniel, J.A. Rongong, Energy dissipation prediction of particle dampers, J. Sound Vib. 319 (2009) 91–118.
[21] C. Gnanasambandham, A. Schönle, P. Eberhard, Investigating the dissipative effects of liquid-filled particle dampers using coupled DEM–SPH methods, Comput. Part. Mech. 6 (2019) 257–269.
[22] Y.-R. Wu, Y.-C. Chung, I.-C. Wang, Two-way coupled MBD–DEM modeling and experimental validation for the dynamic response of mechanisms containing damping particles, Mech. Mach. Theory. 159 (2021) 104257.
[23] Y.-C. Chung, Y.-R. Wu, Dynamic modeling of a gear transmission system containing damping particles using coupled multi-body dynamics and discrete element method, Nonlinear Dyn. 98 (2019) 129–149.
[24] K. Murugaratnam, S. Utili, N. Petrinic, A combined DEM–FEM numerical method for Shot Peening parameter optimisation, Adv. Eng. Softw. 79 (2015) 13–26.
[25] R.E. Spears, S.R. Jensen, Approach for selection of rayleigh damping parameters used for time history analysis, J Press Vessel Technol (2009) 26–30.
[26] Z. Xia, X. Liu, Y. Shan, Application of particle damping for vibration attenuation in brake drum, Int. J. Veh. Noise Vib. 7 (2011) 178.
[27] W. Lin, C. Su, Y. Tang, Explicit time-domain approach for random vibration analysis of jacket platforms subjected to wave loads, J. Mar. Sci. Eng. 8 (2020) 1001.
[28] ISO 226:2003 Acoustics — Normal equal-loudness-level contours |
[Endnote RIS 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
至系統瀏覽論文 (2026-8-31以後開放)
plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
Google bookmarks
del.icio.us
hemidemi
facebook
twitter
google
reddit