• 제목/요약/키워드: shear-thickening fluid damper

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Numerical modelling of a shear-thickening fluid damper using optimal transit parameters

  • Yu, Chung-Han;Surjanto, Yohanes K.;Chen, Pei-Ching;Peng, Shen-Kai;Chang, Kuo-Chun
    • Smart Structures and Systems
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    • 제30권5호
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    • pp.447-462
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    • 2022
  • The viscosity of a shear-thickening fluid damper (STFD) can increase dramatically when the STFD undergoes high-rate of excitation. Therefore, accurate numerical modelling of the STFD has been considered difficult due to this distinct feature. This study aims to develop a numerical model to accurately simulate the response of the STFD. First, a STFD is designed, fabricated, and installed in the laboratory. Then, performance tests are conducted in which sine waves with nine frequencies at three amplitude levels are adopted as the displacement excitations to the STFD. A novel numerical model which contains two parameter sets of the discrete Bouc-Wen model as well as two parameters for transiting the two parameter sets. Therefore, a total number of eighteen parameters need to be identified in the damper model. The symbiotic organisms search is applied to optimize the parameters. Numerical simulation results demonstrate that the proposed STFD model with transit parameter sets outperforms the conventional discrete Bouc-Wen model. The proposed STFD model can be applied to analyses of structures in which STFDs are installed in the future.

유동 모드 댐퍼에서의 Herschel-Bulkley 모델의 유용한 해법 (Useful Guide to Solve Herschel-Bulkley Model in a Flow Mode Damper)

  • 이덕영;박성태
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.784-787
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    • 2003
  • Electrorheological(ER) and magnetorheological(MR) fluid-based dampers are typically analyzed using Bingham-plastic shear model under quasi-steady fully developed flow conditions. A Herschel-Bulkley constitutive shear flow relationship is that the linear shear stress vs. strain rate behavior of Bingham model is replaced by a shear stress that is assumed to be proportional to a power law of shear rate. This power is called the flow behavior index. Depending on the value of the flow behavior index number, varying degrees of post-yield shear thickening or thinning behavior can be analyzed. But it is not practical to analyze the damping force in a flow mode damper using Herschel-Bulkley model because it is needed to solve a polynomial equation. A useful guide is suggested to analyze the damping force in a damper using the Herschel-Bulkley model.

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Herschel-Bulkley 모델에 의한 전기 및 자기장 유체 댐퍼의 준안정 상태 댐핑력 해석 (Quasi-Steady Damping Force of Electro- and magneto-Rheo logical Flow Mode Dampers using Herschel-Bulkley Model)

  • 이덕영;황우석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1298-1302
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    • 2000
  • Electrorheological(HER) and magnetorheologica(MR) fluids have a unique ability to increase the dynamic yield stress of the fluid substantially when electric or magnetic field is applied. ER and MR fluid-based dampers are typically analyzed using Bingham-plastic shear flow analysis under Quasi-steady fully developed flow conditions. An alternative perspective, supported by measurements reported in the literature, is to allow for post-yield shear thinning and shear thickening. To model these, the constant post-yield plastic viscosity in Bingham model can be replaced with a power-law model dependent on shear strain rate that is known as the Herschel-Bulkley fluid model. The objective of this paper is to predict the damping forces analytically in a typical ER bypass damper for variable electric field, or yield stress using Herschel-Bulkley analysis.

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