• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.550-555
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• 2007

This paper is concerned with the active vibration control of building structure by means of the active tuned mass damper and the modified positive position feedback controller. To this end, one-degree-of-freedom spring-mass-damper system equipped with ATMD is considered. The stability condition for the addressed system when applying the proposed PPF controller is derived by Routh-Hurwitz stability criterion. The stability condition shows that the modified PPF controller is absolutely stable if the controller gain is positive, so that the modified PPF controller can be used without difficulty. Theoretical study shows that the modified PPF controller can effectively suppress vibrations as the original PPF controller does in smart structure applications. To investigate the validity of the modified PPF controller, a simple experimental structure with an ATMD system driven by DC motor was built. The modified PPF control algorithm was implemented on Atmel 128 microcontroller. The experimental result shows that the modified PPF controller can also suppress vibrations for the real structure.

• Journal of KSNVE
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• v.5 no.3
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• pp.313-325
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• 1995

Two active/passive vibration dampers were designed to control a cantilever beam first mode of vibration. The active element was a piezoelectric polymer, polyvinlidene fluoride (PVDF). The passive damping was provided by the application of a viscoelastic layer on the surface of the steel beam. Two substantially different damper configurations were designed and tested. One damper consisted of a piezoelectric actuator bonded to one face of the beam, with a viscoelastic layer applied to the other surface of the beam. The second one was composed of a layer viscoeastic layer with one surface bonded to the beam, and with other being constrained by nine piezoelectric actuators connected in parallel. A control law based on the sign of the angular velocity of the cantilever beam was implemented to control the beam first mode of vibration. The piezoelectric sensor output was digitally differentiated to obtain the transverse linear velocity, and its sign was used in the control algorith. Two dampers provided the system a damping increase of a factor of four for the first damper and three for the second damper. Both dampers were found to work well at low levels of vibration, suggesting that they can be used effectively to prevent resonant vibrations in flexible structure from initiating and building up.

• Explosives and Blasting
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• v.33 no.1
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• pp.27-34
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• 2015

Recently, the residence complaints have been increased by blast vibration and noise issue due to increased urban blasting works so that the trouble between construction company and residence have been continuously increased. Deck-charge blasting method using electronic detonator provided not only blast vibration and noise control but also minimized residence complaints through shortening of the blasting period. This blasting method will be widely used for maximizing urban blasting productivity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.306-309
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• 2005

This parer describes the tracking control simulation of 6-DOF shaking table with a bell crank structure, which converts the direction of reciprocating movements. For the Joint coordinate-based control which uses lengths of each actuator, the trajectory conversion process inverse kinematics is performed. Applying the Newton-Euler approach, the dynamic equation of the shaking table is derived. To cope with nonlinear problems, time-delay control(TDC) is considered, which has been noted for its exceptional robustness to parameter uncertainties and disturbance, in addition to steady-state accuracy and computational efficiency. If the nominal model is equal to the real system, joint coordinate-based control can be very efficient. However, manufacturing tolerances installation errors and link offsets contaminate the nominal values of the kinematic parameters used in the kinematic model of the shaking table. To compensate differences between the nominal model and the real system. the joint coordinate-based control using acceleration feedback in the Cartesian coordinate space is proposed.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.4
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• pp.103-114
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• 1998

The floors of building structures equipped with vibrating machines can be susceptible to large vibration as a result of resonance or beating. Such a vibration can be reduced efficiently by using tuned mass dampers. However, the effectiveness of the damper depends greatly on the location and the natural frequency of the damper. To determine the optimum damper location is especially important since the dynamic behavior of a building structure varies with the location of the input loading. To this end, it is intended to decide the location and natural frequency of tuned mass dampers for reducing vibration of both loaded floors and floors located nearby the loaded floors considering the location and frequency components of the loading. The Vector composition method and the super elements are used th obtain the responses in steady states, and the optimum damper location and natural frequencies were found with the given damper mass.

• Annual Conference of KIPS
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• 2012.11a
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• pp.1245-1248
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• 2012

반도체와 LCD 산업분야, 나노급 공정 및 검사기술이 요구되는 산업분야의 수요증가에 따라 초정밀 가공/생산/검사 장비를 설치, 운용하는 FAB. 구조물의 설계요구가 증대되고 있으며, 건물의 환경진동 규제치도 강화되고 있는 실정이다. 이와 같은 대형 구조물에서의 서브 마이크로 수준의 미진동(微振動)을 제어하는 문제는 진동 응답을 결정하는 구조와 재료가 복잡하고 다양한 형태를 갖고 있는 반면, 다루어야 할 동적 응답은 극한적으로 작은 마이크로 이하의 값을 다루어야 하기 때문에 매우 어렵다. 따라서 기존에 이용되고 있는 해석과 실험의 결과만으로는 신모델 설계에 적용하기 어렵다. 따라서, 본 논문에서는 실험적 데이터와 경험적 데이터들을 기반으로 구축된 데이터베이스를 이용하여 새로운 초정밀 FAB. 동적 구조 설계 시스템을 구현한다.

• Annual Conference of KIPS
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• 2012.04a
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• pp.868-871
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• 2012

반도체와 LCD 산업 분야, 나노급 공정 및 검사 기술이 요구되는 산업 분야의 수요 증가에 따라 초정밀 가공/생산/검사 장비를 설치, 운용하는 FAB. 구조물의 설계 요구가 층증대 되고 있다. 이에 따라 건물의 환경진동 규제치도 강화되고 있는 실정이다. 이와 같은, 대형 구조물에서 서브마이크로 수준의 미진동(微振動)을 제어하는 문제는 여전히 어려운 과제로 남아 있다. 이는 진동 응답을 결정하는 구조와 재료가 복잡하고 다양한 형태를 갖고 있는 반면, 다루어야 할 동적 응답은 극한적으로 작은 마이크로(micro) 이하의 값을 다루어야 한다. 그러므로, 기존에 이용되고 있는 해석과 실험의 결과만으로는 신모델 설계에 적용하는 것은 어렵다. 따라서, 본 논문에서는 이러한 영역의 경험적 데이터물을 체계적인 데이터베이스로 구축하여 새로운 동적 구조 설계 기술의 기반을 제공하고자 한다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.6-9
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• 1993

본 연구에서는 엘리베이터 용량, 속도, 제어방식, 아파트 건설공법(현장타설공법 및 조립식공법), 승강로의 벽 및 천장구조 등 여러 요인별로 현장에서 엘리베이터 운행시 소음.진동량을 실측하고 문제점을 파악한 후, 현형 설계여건을 고려하여 PC구조아파트에 적용할 수 있는 효과적인 저감공법을 제시하였다.

• Computational Structural Engineering
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• v.19 no.3 s.73
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• pp.55-62
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• 2006

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.236-239
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• 2005

본 연구에서는 정밀 측정/검사장비의 운영상 발생하는 에러의 원인을 규명하기 위함이다. C/R에 사용되어지는 정밀측정/검사장비는 장비 기초에 대하여 진동허용규제치를 장비 제작업체 제공한다. 이에 C/R 구조 및 장비 기초에 대하여 진동원 차단 방안등을 수행하게된다. 이러한 진동허용규제치를 만족시키기 위한 방안을 수행함에도 공조 소음등과 같은 요인에 의한 장비의 운영상 발생하는 진동과 관련된 에러를 규명하고 이를 제어하기 위한 연구를 수행하였다.