• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.63-68
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• 2010

Satellite structure should be designed to support safely the payload and several actuators under launch and on-orbit environments. After the configuration design of satellite, the structural analysis is performed using quasi-static load provided by launch vehicle manufacturer for detail design of satellite. In order to verify the safety of satellite structure designed using quasi-static loads, launch vehicle manufacturer performs coupled load analysis with satellite and launch vehicle models. For developing satellite, satellite model was reduced into the Craig-Bampton model for coupled load analysis, and delivered to the launch vehicle manufacturer. Launch vehicle manufacturer have done the coupled load analysis, and offered the acceleration and displacement results to the satellite manufacturer. From the analysis results, we have confirmed that satellite is designed safely and there is no possibility of interference and conflict in the inner/outer side of satellite.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.107-119
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• 2018

PHC piles, extension-plate attached PHC piles, and steel pipe attached PHC piles were installed in field test site. Axial compressive static load tests including load distribution test and Pile Driving Analyzer (after driving) were done on the tip-transformed PHC piles and the grouted tip-transformed PHC piles. Load-displacement curves of three different type of PHC piles, which are PHC pile (TP-1), extension plate attached PHC pile (TP-2) and steel pipe attached PHC pile (TP-3), showed almost the same behavior. Thus bearing capacity increase effect of the tip-transformed PHC piles was negligible. Share ratio of side resistance and end bearing resistance for PHC pile, extension plate attached PHC pile, and steel pipe attached PHC pile were 95.8% vs. 4.2%, 95.6% vs. 4.4%, and 97.8% vs. 2.2% respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.739-748
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• 2021

This paper discusses the prediction and validation of design loads of satellite components using modal mass acceleration curve (Modal MAC). To calculate the acceleration upper bound of the satellite components subjected to the launch environment by the Modal MAC, the parameters of SpaceX Falcon 9 launch vehicle were used, and the acceleration upper bound curve in the modal domain was derived. After that, the maximum acceleration loads applied to the satellite components were predicted by combining Modal MAC with the spacecraft interface loads of the satellite/launch vehicle and modal information of the satellite. In addition, the accuracy of the Modal MAC was validated through comparison with the results of the coupled loads analysis using a simple satellite and launch vehicle model.

• Journal of the Korean Geotechnical Society
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• v.26 no.12
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• pp.51-60
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• 2010

Earth pressure due to gravity generally increases linearly with the depth, but the distribution of earth pressure due to surface load depends on the loading condition, the ground condition, and the boundary condition. In this study, the earth pressure on a rigid wall due to the vertical surface load was measured in experiments. Rigid wall was built in the model test box, and it was filled with homogeneous sandy ground (width 30 cm, height 88 cm, length 110 cm). Rigid wall was composed of 8 segments, which were tested on the two load cells. In the tests, we observed the distribution of the earth pressure on the rigid wall depending on the vertical surface load and it's location. According to the test results, the lateral earth pressure due to the vertical surface load showed its maximum value at a constant depth and decreased with the depth, to the negligible value at the critical depth. The critical depth and the depth at which lateral earth pressure reaches its maximum were not decided by the magnitude of the vertical surface load. They were dependant on the distance from the rigid wall.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.2
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• pp.42-49
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• 2023

When designing fixed jacket structures, overseas design standards are applied due to the absence of domestic design methods. Although the US API standards are mainly applied, API RP 2A suggests two design methods: the allowable stress design method (WSD) and the load resistance coefficient method (LRFD), and is applied according to the designer's judgment. In this study, the stress ratio of the two design methods was reviewed and compared using SACS, an analysis program dedicated to marine structures, for fixed marine structures actually installed on the domestic coast. As a result of the review, it was found that the LRFD design method showed a greater stress ratio for extreme load analysis and transportation analysis, and the WSD design method showed a greater stress ratio for loading and lifting. Therefore, when applying the design method, it is considered appropriate to select the final design method considering safety and economic feasibility after conducting an applicability review for the two design methods.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.955-963
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• 2006

As the geometrical characteristic of the curved bridge, the seismic response of curved bridges are different from straight bridges. This study analyzed the seismic response of the curved bridges considering diverse factors such as radius of curvature, direction of seismic load and support condition. The improved simple modeling of the curved bridge for seismic analysis is proposed, and it is compared with the detail modeling in order to verify the simple modeling. Three simply supported curved bridges and six 3-span continuous bridges are selected for seismic analysis. The behavior of curved bridges are evaluated in terms of the displacement and the force at supports and piers under seismic load applied in various directions. The results of this study show that upward reaction force may appear in simply supported curved bridge under seismic load. And continuous curved bridges are affected by the direction of the seismic load.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6A
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• pp.809-817
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• 2008

Recently, the external prestressing method is being much frequently used in strengthening reinforced concrete structures because of it's excellent load resistance and serviceability increases comparing to other strengthening methods. However, it is true that the research on fatigue performance of concrete structures strengthened by the external prestressing using FRP tendons is rare. Therefore, the purpose of this study is to evaluate the safety and feasibility of the external prestressing method by analyzing the characteristics of the reinforced concrete beam strengthening using FRP tendons under repeated loads. Test variables adopted in this experimental study are the types of external prestressing material (steel or FRP tendon) and the repeated load ranges. The repeated load range have the minimum 50% of yield load of reinforced concrete beam and the maximum 70-85%. The test beams are loaded by 4 point loadings with 3 Hz sine wave. From this experimental study, it is confirmed that the reinforced concrete beams strengthened using FRP tendons have sufficient safety against fatigue, especially in FRP tendon itself, tendon at deviators and tendon at anchorages.

• 한국도로학회:학술대회논문집
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• 2011.03a
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• pp.201-204
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• 2011

• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.117-117
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• 2006

• 한국도로학회:학술대회논문집
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• 2010.09a
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• pp.477-482
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• 2010