• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.1
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• pp.171-180
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• 2005

In this study the seismic performance of a three-story knee-braced moment-resisting frame (KBMRF), which is typically employed to support pipelines for oil or gas, was investigated. Nonlinear static pushover analyses were performed first to observe the force-displacement relationship of KBMRF under increasing seismic load. The results show that, when the maximum inter-story drift reached 1.5% of the story height, the main structural members, such as beams and columns, still remained elastic. Then nonlinear dynamic time-history analyses were carried out using eight earthquake ground motion time-histories scaled to at the design spectrum of UBC-97. It turned out that the maximum inter-story drift was smaller than the drift limit of 1.5 % of the structure height, and that the columns remained elastic. Based on these analytical results, it can be concluded that the seismic performance of the structure satisfies all the requirements regulated in the seismic code.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.5 s.45
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• pp.11-19
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• 2005

Seismic design of a building is usually performed by using the linear static procedure. However, the actual behavior of the building subjected to earthquake is inelastic and dynamic in nature. Therefore, inelastic dynamic analysis is required to evaluate the safety of the structure designed by the current design codes. For the validation, a RC special moment resisting frame building was chosen and designed by IBC 2003 representing new codes. Maximum plastic rotation and dissipated energy of some selected members were calculated for examining if the inelastic behavior of the building follows the intention of the code, and drift demand were calculated as well for checking if the building well satisfies the design drift limit. In addition, the effect of including internal moment resisting frames (non lateral resisting system) on analyses results was investigated. As a result of this study, the building designed by IBC 2003 showed the inelastic behavior intended in the code and satisfied the design drift limit. Furthermore, the internal moment resisting frames should be included in the analytical model as they affect the results of seismic analyses significantly.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.792-795
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• 2008

AGT system is a kind of light railway train. AGT system use of concrete track and rubber tire, so it can be reduce the noise and vibration, compare to the normal train system. And, the dynamic responses of normal bridge are influenced by the dynamic characteristics of bridge, the speed of vehicle and the surface roughness of railway. But the AGT system bridge is influenced not only the above facts but also the guiderail unevenness, because, AGT vehicle steered by guiderail. So, in this study, optimized service condition is suggested for the design and operation of AGT system, by the means of experimental study. The experiments are executed for PSC bridge with length of 30m, at the AGT test line in Kyongsan. The test results are compared and investigated according to the prominence. In the test result, the guiderail prominence influenced on the dynamic response of bridge. It shows a increase as compared with no guiderail prominence in the dynamic response value acceleration, displacement, stain.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.851-858
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• 2023

Purpose: A study was conducted to ensure the structural safety of a raised girder bridge with improved cross-sectional efficiency compared to the conventional PSC girder. For this purpose, the cross-sectional specifications such as girder length, height, and width were determined, the arrangement of the tendons was designed, and the practical performance of the raised girder under static and dynamic loads was verified. Method: The static performance experiment examined the serviceability limit state by measuring behavioral responses such as deflection and cracking to primary and secondary static loads. In addition, the dynamic load loading experiment measured the acceleration and displacement behavior response over time to calculate the natural frequency and damping ratio to examine the usability limit state. Result: As a result of the static performance test, the deflection value based on the maximum applied load showed stable behavior, and the crack width measured at the maximum applied load level was very small, satisfying the serviceability limit state. In addition, a natural frequency exceeding the natural frequency calculated during the design of the dynamic loading experiment was found, and a damping ratio that satisfies the current regulations was found to be secured.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.289-294
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• 2011

In this study, the seismic analysis of traveling sea water screen for nuclear power plant was performed using finite element model. For qualification of traveling sea water screen, the response spectrum analysis was performed using the given operating basis earthquake(OBE) and safe shutdown earthquake(SSE) floor response spectrum. Dynamic analysis of water sea traveling screen was performed using finite element method. The analytical maximum displacements of traveling sea water screen were 2.5 mm under OBE condition and 4.6 mm under SSE condition. The maximum stresses of traveling sea water screen were 24 MPa under OBE condition and 44 MPa under SSE condition, that this results were 18 %, 27% of yield strength of material. Thus, it can shown that the structural integrity of traveling sea water screen has a stable structure for seismic load conditions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.360-366
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• 2004

This paper presents a method analyzing the motion of cylindrical buoy moored at 2 points and tensions action on each mooring line under the action of periodic waves. It was found that submersible buoy was more effective than floating one in the severe conditions considering its dynamic motions, wave forces, and mooring line tensions. The wave induced its dynamic responses and mooring line tensions peak when the ratio d/${\lambda}$ of the buoy length d to the waves length ${\lambda}$ was 0.66 due to its natural frequency. The results of this study were in agreement with the existing measurement ones, however, further verifications are needed considering resonance of cylindrical buoy and its displacements to wave height by a series of model tests.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.114-122
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• 2018

This study presents the emergency assessment method about seismic safety of cable-supported bridges using seismic acceleration sensors installed on the primary structural elements of them. The structural models of bridges are updated iteratively to make their dynamic characteristics to be similar to those of real bridges based on the comparison of their natural frequencies with those of real bridges estimated from acceleration data measured at ordinary times by the seismic acceleration sensor. The displacement at the location of each seismic acceleration sensor is derived by seismic analysis using design earthquake, and the peak value of them is determined as the disaster management criteria in advance. The displacement time history is calculated by the double integration of the acceleration time history which is recorded at each seismic acceleration sensor and filtered by high cut(low pass) and low cut(high pass) filters. Finally, the seismic safety is evaluated by the comparison of the peak value in calculated displacement time history with the disaster management criteria determined in advance. The applicability of proposed methodology is verified by performing the seismic safety assessment of 12 cable-supported bridges using the acceleration data recorded during Gyeongju earthquake.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.105-113
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• 2018

The proposed model to predict the bridge load carrying capacity uses the impact response spectrum. The spectrum is based on Euler-Bernoulli beam and the center of the bridge width for the moving load location. Therefore, it is necessary to investigate the eccentric moving load effects on the impact factor and response factor. For this, this study considers 10 m width and two-lane simply supported slab bridges and performs the moving load analysis to investigate the variations of peak impact factor and corresponding response factor. The numerical results show that the eccentric load increases both the static and dynamic displacements, but the impact factor is decreased since the incremental amount of static displacement is bigger than that of dynamic displacement. However, the difference of the impact factors between the center and eccentric loadings is small showing less than 0.5%p. In the response factor, the eccentric loading increases both the static and dynamic response factors, compared to the center loading. The difference of the response factor is only 0.18%p. It shows that the eccentric loading has very small effects on the response factor, thus the impact factor response spectrum which is generated based on the center moving load can be used to determine the response factor.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.137-142
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• 2011

A bimodal tram is a new design vehicle introduced to improve a current transportation system, and it has advantages of a bus and a subway. A pipe truss bridge, an exclusive road of the bimodal tram, is constructed for introduction of the bimodal tram. An analysis of dynamic response characteristics is required because this new bridge has never constructed before. A speed increasing test on the pipe truss bridge was conducted with attaching a sensor to bottom of the bridge. Also, Dynamic response characteristics were analyzed by measuring displacements, the maximum vertical and horizontal acceleration about the new bridge through the experiment.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.201.1-201.1
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• 2016

전주된 Invar (Fe-35%Ni) 박판 위에 증착된 Cu 박막은 스퍼터 전력량이 증가할수록 증착속도가 증가하였다. Cu/Invar 박판이 Invar 박판보다 면저항 값이 34%로 작았다. Invar 박판 위에 Cu가 증착되면 최대자화와 투자율은 각각 40.3, 65.0 [%] 감소하였다. Cu 박막의 탄성하강강성도, 마찰계수, 피로한계는 각각 45, 0.130, 0.093 이었다. 동적 나노 압침법으로 얻은 Invaar/Cu 박막의 하중-시간-변위 곡선의 가장 큰 차이는 탄성하강강성도(elastic stiffness) 이었다. 미세경도와 나노경도의 실험적 관계식은 $Y[GPa]=9.18{\times}10^{-3}X[Hv]$ 이었다. 나노압침선단의 하중분포를 이차원 선형 및 비선형 유한요소해석을 통하여 1.0 [mN] 의 정적하중을 가한 Cu 박막은 486 [mN] 으로 예측되었다. 이는 표면탐침현미경으로 관찰한 압흔의 변형정도와 유사한 경향을 보였다.