• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1355-1360
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• 2005

Periodic structures can be applied as a MEMS(micro-electro-mechanical system) sensor or actuator due to low energy loss and wideband frequency response. The dynamic behavior of a mistuned periodic structure Is dramatically changed from that of a perfectly tuned periodic structure. The effects of mistuning, coupling stiffness, and driving point on the forced vibration responses of a simple periodic structure ate investigate4 through numerical simulations. On the basis of that, one can design effective and reliable MEMS components using periodic structures.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.425-432
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• 2001

This paper presents the studies of the characteristics of dynamic behavior of single layer latticed domes with laminated rubber bearing and establishes the effectiveness of the system. The base isolation system installed between base and structures reduces the responses due to earthquake motions and increases the natural period of structures. Numerical analysis is carried out using modal superposition method and Newmark-βmethod which is linear acceleration method with (equation omitted) : 1/2 and β : 1/6. The time interval Δt for response calculation is 0.001 sec. Damping ratio is 2 % as Rayleigh damping and El Centro NS(1940) as earthquake motion is the input excitation data. The acceleration response of dome with base isolation is reduced to 30 % of the response of non-isolation system. From the results of the numerical studies on the models, it is confirmed that base isolation system effectively suppresses the responses of the domes subjected to horizontal earthquakes.

• Structural Engineering and Mechanics
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• v.35 no.3
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• pp.365-377
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• 2010

In the present article, effect of non-uniform excitation due to spatially variation of seismic input on nonlinear response of concrete gravity dams is considered. The reservoir is assumed compressible. Isotropic damage mechanics approach is used to model static and dynamic nonlinear behavior of mass concrete in 2D space. The validity of utilized nonlinear model is considered using available theoretical results under static and dynamic conditions. The tallest monolith of Pine Flat dam is selected as a case study. Two cases are analyzed for considering the effect of limited wave propagation velocity on seismic behavior of the dam-reservoir system in which travelling velocities are chosen as 2000 m/s and infinity. It is found that tensile damage in neck and toe regions and also, in the vicinity of the base increase when the system is excited non-uniformly.

• Structural Engineering and Mechanics
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• v.11 no.3
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• pp.273-286
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• 2001

Viscoelastic (VE) dampers have shown to be capable of providing structures with considerable additional damping to reduce the dynamic response of structures. However, the VE material appears to be sensitive to the variations in ambient temperature and vibration frequency. To minimize these effects, a new VE material has been developed. This new material shows less sensitivity to variations in vibration frequency and temperature. However, it is highly dependent on the shear strain. Experimental studies on the seismic behavior of a 2/5 scale five-story steel frame with these new VE dampers have been carried out. Test results show that the structural response can be effectively reduced due to the added stiffness and damping provided by the new type of VE dampers under both mild and strong earthquake ground motions. In addition, analytical studies have been carried out to describe the strain-dependent behavior of the VE damper. The dynamic properties and hysteresis behavior of the dampers can be simulated by a simple bilinear model based on the equivalent dissipated energy principle proposed in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.475-482
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• 2001

Stadium stand could be led to significant dynamic response due to rhythmical activities of spectator. The dynamic loads induced by spectators movements are considered as static loads in design standard of many countries but these loads have dynamic characteristics. So, it is desirable to apply measured dynamic loads created by spectator activities and to analyze the dynamic behavior of stadium system. The precise investigation of the dynamic loads on stadium structures and the accurate analysis of dynamic behavior of stadium systems are demanded for effective design. As the floor mesh of stadium stand is refined, the number of nodes increase in numerical analysis. So it is difficult to analyze entire stadium structures and much more computer memory are necessary for vibration analysis of stadium system. In this study, the various dynamic loads induced by spectator movements are measured and analyzed. And new modeling method that reduce the nodal points of stadium systems are introduced. Vibration analysis of stadium system is executed to inspect the accuracy and the efficiency of proposed method in this paper.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.193-197
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• 2004

A finite element analysis is proposed to assess the dynamic response due to impulse excitation of UUV cable system. 'Onnuri'. a special purpose ship of KORDI. was adopted as a support vessel. and all the main dimensions and properties used in the analysis were determined by the support vessel. Transient dynamic response analysis was carried out for various types of impulses. and the magnitude of cable tension induced by impulse was discussed as results.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.161-168
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• 2004

The dynamic instability of snapping phenomena has been studied by many researchers. Few papers deal with dynamic buckling under loads with periodic characteristics, and the behavior under periodic excitations is expected to be different from behavior under STEP excitations. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidally shaped arch structures are subjected to sinusoidally distributed excitations with pin-ends. The mechanisms of dynamic indirect snapping of shallow arches are especially investigated under not only STEP function excitations but also under sinusoidal harmonic excitations, applied in the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equation of motion, and examined by Fourier spectral analysis in order to get the frequency-dependent characteristics of the dynamic instability for various load levels.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.133-138
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• 2008

In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.119-124
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• 2004

The effect of soil-structure interaction becomes important in the design of civil structures such as long-span bridges, which are constructed in the site composed of soft soil. Many methodologies have been developed to account for the proper consideration of soil-structure interaction effect. However, it is difficult to estimate soil-structure interaction effect accurately becaused of many uncertainties. This paper presents the results of study on soil-structure interaction and dynamic response of a long-span bridge designed in the site composed of soft soil. The effect of the soft soil was evaluated by the use of computer program SASSI and a long-span bridge structure was modeled by finite elements. Dynamic response characteristics of a long-span bridge considering soil-structure interaction wereinvestigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.1
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• pp.67-74
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• 2004

The dynamic instability for snapping phenomena has been studied by many researchers. Few paper deal with the dynamic buckling under the load with periodic characteristics, and the behavior under periodic excitation is expected the different behavior against STEP excitation. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidal shaped arch structures are subjected to sinusoidal harmonic excitation with pin-ends. By using Newmark- β method, we can get the nonlinear displacement response, and using this analyze characteristics of the dynamic instability through the running response spectrum by FFT(Fast Fourier Transform).