• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.329-334
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• 2002

Preliminary test for the design and construction of a tuned dynamic absorber is a conducted. Proposed tuned dynamic absorber is a cantilevered beam type, and is supposed to adjust its natural frequency according to the changing operation condition of the primary system. The modal mass of the dynamic absorber is the easiest to control, therefore, the position of the attached mass of the dynamic absorber is considered as the main design parameter of the absorber. The effect of the dynamic absorber is experimentally verified under various operation conditions of the primary system.

• Journal of KSNVE
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• v.10 no.2
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• pp.325-330
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• 2000

A dynamic absorber is used to protect the primary vibration system under the steady-state harmonic disturbance. In a number of cases it appears expedient to install several absorbers of smaller masses instead of one. This may be due to the need of distribute the absorber's response along the construction, restrictions on the absorber's installation. So, we studied characteristics of the primary vibration system for the optimal natural frequency ratio and the optimal damping ratio of serial multi-dynamic absorber. Also we obtained the optimum values of the serial multi-dynamic absorber parameters using computer simulation for the damped primary vibration system. In designing multi-dynamic absorber, we presented for the optimal natural frequency and the optimal damping ratio of multi-dynamic absorbers.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.35-36
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• 2006

This study is mainly concerned with vibration control of L-type reciprocating air compressor by a dynamic vibration absorber. The dynamic vibration absorber of reciprocating air compressor was designed for constant revolution running condition. For the review, Vibration test was conducted for the performance appraisal of installed dynamic vibration absorber in the reciprocating air compressor. As a result of the test, the performance of dynamic vibration absorber was satisfactory.

• Journal of KSNVE
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• v.9 no.1
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• pp.121-130
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• 1999

Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.2
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• pp.41-48
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• 2018

In this study, the dynamic absorber and the damper are applied to improve the seismic performance of the piping system, and their quantitative effects on the piping system performance are examined. For this purpose, the response performances of piping system applied with the dynamic absorber/damper are compared with those of the original piping system. Firstly, the frequency response analyses of the piping system with the presence or the absence of dynamic absorber/damper are performed and these results are compared. It has been shown that the maximum acceleration response per the frequency of the piping system is considerably reduced by installing the dynamic absorber and the damper. Secondly, the seismic responses of the piping systems with and without dynamic absorber/damper are compared. As a result of the numerical analyses, it is confirmed that key responses are reduced by 17%-63% due to the installation of the dynamic absorber and damper. Finally, as a result of the seismic performance evaluation, it is confirmed that the HCLPF (High Confidence of Low Probability of Failure) seismic performances are increased by 1.22 to 2.70 times with respect to the failure modes with an aid of the dynamic absorber and damper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.5
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• pp.83-89
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• 2010

In this paper, the dynamic response of a CNC 5 Axles machining center was analyzed and then controlled passively by using the dynamic absorber. For the simplification of the theoretical approach, the CNC 5 Axles machining center was modeled as a flexible beam(Bed) having a point mass(Column), two discrete systems(a Table-set and a dynamic absorber). Specifically by using the dynamic absorber, the dynamic response of a Table-set which be caused by the vibration of a flexible beam, was reduced down to the infinitesimal level. The optimal design factors of the dynamic absorber were obtained from the minimization of the cost function. It was found that the natural frequencies of a UT-380 machining center be varied due to the movement of the Table-set. In view of the dynamic response of a Table-set, the larger spring stiffness and mass of the dynamic absorber were found to give the greater reduction.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.111.4-111
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• 2001

In this paper, an adaptively tuned dynamic absorber is proposed. The adaptively tuned dynamic absorber is a dynamic absorber whose stiffness is tuned so that the natural frequency of the absorber coincides with the operating or natural frequency estimated by an adaptive algorithm. The feature of this absorber is as follows. It has an electrodynamic device for the stiffness control. Using Lorenz´s force, it changes the stiffness by changing the applied current. The change of stiffness results in the natural frequency shift, because its mass and damping coefficient are fixed. We may reduce the vibration of the overall system by tuning the natural frequency of the dynamic absorber to the resonant frequency of the structure, when the dominant single tone oscilation occurs in the system ...

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.11
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• pp.1064-1070
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• 2010

In this work, a dynamic absorber with a plate-type cantilever using magnetic force is proposed to reduce the vibration of a compressor directly. The dynamic absorber using magnetic force has some advantages of easily tuning the control frequency by adjusting the magnet spacing and obtaining wider control frequency band. The dynamic absorber is designed theoretically and tested experimentally to estimate the control frequency band. When the compressor is equipped with the dynamic absorber, the vibration of compressor and the noise level of refrigerator are reduced by 30 % and 3.2 dB respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.113-118
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• 2011

Many kinds of dynamic absorbers have been used to reduce the vibration of machineries and structures. In the typical ones, however low damping capacity, durability and limited install condition restrict their application. In this study, high damped dynamic absorber was proposed for diesel generator set. Developed absorber is composed with mass and coil springs. Silicone oil was filled inside the narrow gap between mass and casing. Viscous damping of silicon oil act as additional damping so that proposed dynamic absorber is suitable for D/G set which have adjacent resonance frequency to operation speed. The performance of the dynamic absorber was confirmed through the actual test on diesel engine generator set.

• Journal of KSNVE
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• v.9 no.6
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• pp.1166-1172
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• 1999

This paper is the experimental study on the endurance characteristics of the dynamic absorber for the vibration reduction of the 4WD(4 Wheel drive) vehicle's powertrain. Employing the vehicle speed, natural frequencies of damper, modal testing results of powertrain and the weighting factor, the improved endurance test conditions are suggested to enlarge the life time of the dynamic absorber. The test results show that the life time of the dynamic absorber for Z-direction(up and down) has no problems, but the characteristics of X-direction (fore and after) will be sensitive to endurance characteristics of dynamic absorber.