• Structural Engineering and Mechanics
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• 제11권6호
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• pp.617-636
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• 2001

For the potential application of smart materials to seismic structural control, this paper reviews seismic control techniques for civil engineering structures, and developments of smart materials for vibration and noise control. Analytical and finite element methods adopted for the design of distributed sensors/actuators using piezoelectric materials are discussed. Investigation of optimum position of sensors/actuators and damping are also outlined.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.375-380
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• 2004

Seismic Isolation and Shock/vibration Control Laboratory has performed the National Research Laboratory(NRL) project, 'Design and Application of Control Devices against Earthquake/Shock/Vibration'. In this project, the prototypes of the vibration control devices for structural control against earthquake and wind were developed and verified their performances. And also, the computer programs were developed for the seismic response analysis and the optimum design of the base-isolated structures with vibration control devices. This paper introduces the developed vibration control devices and computer programs.

• 국제초고층학회논문집
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• 제11권3호
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• pp.207-219
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• 2022

During the structural design of urban over-track high-rise buildings, two problems are most likely encountered: the abrupt change of story stiffness between the podium and the upper towers, as well as the demand for train-induced vibration control. Traditional earthquake-resistant structures have to be particularly designed with transfer stories to meet the requirement of seismic control under earthquakes, and thus horizontal seismic isolation techniques are recommended to solve the transfer problem. The function of mitigating the vertical subway-induced vibration can be integrated into the isolation system including thick rubber bearings and 3D composite vibration control devices. Engineering project cases are presented in this paper for a more comprehensive understanding of the engineering practice and research frontiers of urban over-track high-rise buildings in China.

• 한국해양공학회지
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• 제24권5호
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• pp.48-54
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• 2010

The analysis of the seismic risk of an offshore structure with a control device is presented. First, a probability density function was developed to represent seismic hazard, and seismic fragility under artificial earthquake conditions was determined. Fragility curves for an offshore structure with both passive and active control devices were determined. Displacement criteria were set to evaluate the performance of the structure. Based on numerical analysis, the seismic risk to the structure was considerably reduced when the structure had a seismic control device. The seismic risk to the actively controlled structure was decreased by 80% compared to the uncontrolled case. Reasonable performance evaluations of offshore structure with control devices can be conducted through risk analysis.

• Structural Monitoring and Maintenance
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• 제3권2호
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• pp.157-174
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• 2016

Based on classical viscoelastic damper, a brand-new damper is designed by the change of simple construction to implement vibration control for both translational vibration and rotational vibration simultaneously. Theoretic analysis has been carried out on the restoring force model and the control parameters. Two improved models are presented to obtain high simulation precision. The influence of the size, shape of the viscoelastic material, the ambient temperature and the response frequency on the vibration control effect is analyzed. The numerical results show that the new type viscoelastic damper is capable of mitigating the multi-dimensional seismic response of offshore platform and the response control effect has complicated relations with aforementioned related factors.

• 한국지진공학회논문집
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• 제10권6호
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• pp.67-77
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• 2006

우리나라는 일본이나 미국의 서부지역처럼 지진위험도가 매우 높은 지역이 아니다. 그러므로 1988년에 처음으로 내진설계기준이 도입될 때까지 거의 대부분의 구조물들이 지진의 영향을 고려하지 않고 설계되었다. 원자력발전소나 액화천연가스(LNG) 저장 탱크 등의 구조물에 면진 기술이 적용되었지만 우리나라의 기술자들은 면진이나 진동제어에 대해서는 별로 관심이 없었으며 이러한 것은 강진지역에서나 필요한 기술로 생각하였다. 그러나 이러한 기술은 우리나라와 같은 약진지역에서 더 효과적으로 지진과 바람의 영향을 저감시킬 수가 있는 것이다. 다행히 근래에는 극히 소수이기는 하지만 우리나라에서도 면진과 진동제어 기술을 적용하는 교량이나 건물의 수가 점차 늘어나고 있어서 지진이나 바람 등의 영향에 대하여 보다 적극적인 대처를 하기 시작하였다. 그러나 건축 구조물의 면진이나 진동제어에 대하여 설계기준이 제대로 마련되어 있지 않아서 이러한 기술을 적용하는데 실제적으로는 많은 어려움을 겪기도 하는 것이 현실이다. 따라서 우리나라에서도 이러한 기술을 적용할 수 있는 법적 근거를 마련하는 것이 시급한 과제라고 볼 수 있다.

• 한국소음진동공학회논문집
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• 제15권6호
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• pp.652-659
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• 2005

In this paper, seismic qualification analysis for the Plant control Panel is carried out to confirm the structural integrity under the seismic conditions represented by required response spectra(RRS). The finite element method(FEM) is used for the analysis and a mode combination method is adopted to obtain a more reliable spectrum analysis results. In addition, the experimental analysis is performed to compare the reliability of the analytical results. The analysis results shows that the plant control panel system is designed to have the dynamic rigidity with no resonance frequency below 33 Hz. The analytically calculated maximum stress of the plant control panel system is $36\%$ of the field strength of material, thus it can be shown that the system has a stable structure for the seismic load.

• Structural Engineering and Mechanics
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• 제87권2호
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• pp.117-127
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• 2023

To efficiently attenuate seismic responses of a structure, a novel pneumatic-driven active dynamic vibration absorber (PD-ADVA) is proposed in this study. PD-ADVA aims to realize closed-loop control using a simple and intuitive control algorithm, which takes the structure velocity response as the input signal and then outputs an inverse control force to primary structure. The corresponding active control theory and phase control mechanism of the system are studied by numerical and theoretical methods, the system's control performance and amplitude-frequency characteristics under seismic excitations are explored. The capability of the proposed active control system to cope with frequency-varying random excitation is evaluated by comparing with the optimum tuning TMD. The analysis results show that the control algorithm of PD-ADVA ensures the control force always output to the structure in the opposite direction of the velocity response, indicating that the presented system does not produce a negative effect. The phase difference between the response of uncontrolled and controlled structures is zero, while the phase difference between the control force and the harmonic excitation is π, the theoretical and numerical results demonstrate that PD-ADVA always generates beneficial control effects. The PD-ADVA can effectively mitigate the structural seismic responses, and its control performance is insensitive to amplitude. Compared with the optimum tuning TMD, PD-ADVA has better control performance and higher system stability, and will not have negative effects under seismic wave excitations.

• 한국안전학회지
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• 제37권3호
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• pp.45-51
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• 2022

This paper focuses on a recently proposed asymmetric base-isolation coupling control system (ABiCS) for the vibration control of adjacent twin buildings. The ABiCS consists of inter-story diagonal dampers, a connecting damper between the two buildings, and a seismic isolation device at the base floor of one building. To investigate the control characteristics of ABiCS, a parametric study was performed by numerically simulating the 20-story twin buildings. In the parametric study, the control capacities of the inter-story diagonal dampers, connecting damper, and seismic isolation device were considered as varying parameters. The parametric study results indicate that the connecting damper between the two buildings reduces the responses of both buildings only at optimal or near-optimal capacity. In addition, adjusting the stiffness of the base isolation is found to be the most effective method for improving seismic performance and achieving cost-effectiveness. Accordingly, we presented a scenario-based performance improvement approach in which reducing the stiffness of the base isolation device could be an effective technique to improve the seismic performance of both buildings. However, note that checking the maximum allowable displacement of the base isolation device is essential.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.498-498
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• 2001

Seismic qualification of the Main Control Boards for nuclear power plants has been performed with the guideline of AS ME Section III. US NRC Reg. Guide and IEEE 344 code. The analysis model of the Main Control Boards is consist of beam. shell and mass element by using the finite element method. and, at the same time. the excitation forces and other operating loads for each model are encompassed with respect to different loading conditions. As the fundamental frequencies of the structure are found to be less than 33Hz. which is the upper frequency limit of the seismic load, the response spectrum analysis using ANSYS is performed in order to combine the modal stresses within the frequency limit. In order to confirm the structural and functional integrity of the major components, modal analysis theory is adopted to derive the required response spectrum at the component locations. As all the combined stresses obtained from the above procedures are less than allowable stresses and no mechanical or electrical failures are found from the seismic testing, it concludes the Main Control Boards is dynamically qualified for seismic conditions. Although the authors had confirmed the structural and functional integrity of both Main Control Boards and all the component, in this paper only the seismic analysis of the Main Control Board is introduced.