• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.489-494
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• 2002

This paper presents hydraulic model which can capture the hysteric damping force behavior of ER damper. A flow mode rue ER damper is manufactured, and its field-dependent damping forces are measured. Newly proposed hydraulic model which derived from physical hydro-mechanical parameters of ER damper are conventional Bingham model are investigated to represent the field-dependent damping force characteristics of ER damper. After principal parameters of two models are estimated from the measured damping forces data, the force vs velocity hysteresis cycles are then reconstructed. The results show that the proposed hydraulic model can capture the hysteresis behavior of ER damper accurately.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.140-146
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• 2008

A friction damper is installed in the passenger car driveline in order to dissipate the torsional vibration energy. The frictional damping hysteresis has considerable influences on the driveline vibration characteristics and, therefore, it is one of the most important parameters in the damper design. To investigate the hysteresis effects on the driveline vibration, a dynamic model of the passenger car driveline with manual transmission has developed, and simulations were executed on the several different driving conditions for various hysteresis values. To verify the model, vehicle tests are preformed and the test data were compared with the simulations results. The simulation and test results show good agreements and the model could be used to determine the optimal hyteresis values in early design stage of the damper.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.1
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• pp.189-197
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• 2001

This paper presents hysteresis models of damping forces of a magneto-rheological (MR) damper which is applicable to a middle-sized passenger vehicle. After manufacturing a cylindrical type of the MR damper, its field-dependant damping force and hysteresis behavior are experimentally evaluated. Three different models ; Bingham model, Bouc-Wen model and Polynomial model are provided to predict the hysteretic damping force. The damping force characteristics predicted from three different models are compared with the measured results under various excitation conditions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.381-386
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• 2007

This paper presents vibration control performances of a commercial magnetorheological (MR) suspension via new control strategy considering hysteresis of the field-dependent damping force of MR damper. A commercial MR damper which is applicable to high class passenger vehicle is adopted and its field-dependent damping force is experimentally evaluated. Preisach hysteresis model for the MR damper is identified using experimental first order descending (FOD) curves. Then, a feed-forward compensation strategy for the MR damper is formulated and integrated with a linear quadratic regulation (LQR) feedback controller for the suspension system. Control performances of the proposed control strategy for the MR suspension is experimentally evaluated with quarter vehicle test facility.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.3
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• pp.315-322
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• 2008

This paper presents vibration control performances of a commercial magnetorheological(MR) suspension via new control strategy considering hysteresis of the field-dependent damping force of MR damper. A commercial MR damper which is applicable to high class passenger vehicle is adopted and its field-dependent damping force is experimentally evaluated. Preisach hysteresis model for the MR damper is identified using experimental first order descending(FOD) curves. Then, a feed-forward compensation strategy for the MR damper is formulated and integrated with a linear quadratic regulation(LQR) feedback controller for the suspension system. Control performances of the proposed control strategy for the MR suspension is experimentally evaluated with quarter vehicle test facility.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.59-66
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• 2003

A novel application of nano-technology in the field of engineering, called colloidal damper, is investigated. This device is complementary to the hydraulic damper, having a cylinder-piston construction. Particularly for colloidal damper, the hydraulic oil is replacedby a colloidal suspension, which is consisted from a nano-porous matrix with controlled architecture and a lyophobic fluid. In this experimental work, the porous matrix is composed from silica gel, with labyrinth architecture, coated by organo-silicones substances in order to achieve a hydrophobic surface. Water is considered as associated lyophobic fluid. The colloidal damper test rig and the measuring technique of the hysteresis are described. the influence of the hydrophobicity level upon the colloidal damper hysteresis is investigated, for silica gels with similar pores distribution. A certain desired shape of the hysteresis can be achieved by employing mixture of silica gels with different level of hydrophobicity and/or architecture. With these results, it is believed that the proposed damper can be designed and be applied to the desired structure.

• Journal of Biosystems Engineering
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• v.31 no.4 s.117
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• pp.315-322
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• 2006

A torsional damper comprised of two stage pre-dampers was used to reduce the rattle noise generated in the PTO gear box of a direct engine-PTO driveline of agricultural tractors. It was designed and mounted to the engine flywheel to reduce the torque fluctuation-induced speed variations at the driving gears in the PTO gearbox, which were found to be main cause of the rattle noise. The effects of a hysteresis torque and a torsional stiffness of the damper on the speed variation were analyzed using an 11 degree of freedom non-linear model of the damped PTO driveline. The torsional damper was represented by a single degree of freedom model with 7 parameters. Under a constant hysteresis torque, velocity variation was reduced with decrease in the torsional stiffness of the damper. The velocity variation was also decreased with decrease in the hysteresis torque under a constant torsional stiffness. Optimum values of the torsional stiffness and hysteresis torque were obtained by the model simulation for the PTO driveline under the study. When the optimum values of the damper were used, the sound pressure level of the rattle noise was reduced by 81%, resulting in a reduction of 15dB(A). The optimum damper also reduced the engine speed variation, resulting in a reduction of 80% at the driving gears in the PTO gearbox. The torsional damper showed a good performance in reducing the rattle noise caused by the speed variation in the direct engine-PTO driveline.

• Journal of Aerospace System Engineering
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• v.7 no.1
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• pp.44-49
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• 2013

Passive attitude stabilization method has been widely used for attitude determination and control of cube satellite due to its advantage of system simplicity. In this paper, permanent magnet stabilization method for application of cube satellite attitude control has been introduced and its performance with and without hysteresis damper system has been investigated through a numerical simulation. The simulation results indicate that the permanent magnet stabilization combined with hysteresis damper shows much higher stabilization performance than the system without damper system.

• 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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.7
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• pp.659-666
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• 2009

This paper proposes a new method for dynamic modeling of electrorheological(ER) damper considering fluid compressibility. After describing configuration and operating principle of the ER damper, a quasi-static modeling of the ER damper is conducted on the basis of Bingham model of ER fluid. Subsequently, the dynamic model for describing the ER damper considering compressibility of ER fluid and gas chamber is obtained using the lumped parameter method. This method includes dynamic motions of annular duct, upper chamber, lower chamber and connecting pipe. The hysteresis behavior of the ER damper is evaluated through computer simulations and compared with experimental results. In addition, the hysteresis behavior due to the compressibility of ER fluid and gas chamber is investigated through computer simulations.