• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.3
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• pp.35-40
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• 2010

The specially orthotropic plate theory is used for analysis of panels made of girders and cross-beams. The cross-sections of both girders and cross-beams are H-types. The results of application of this method to rolled beam bridge by using specially orthotropic plate theory is presented. The result is compared with that of the beam theory. Finite difference method is used for this purpose. The influence of the $D_{22}$ stiffness on the natural frequency is rigorously investigated. According to numerical examination given in this paper, the result by the plate theory is 2.43 times stiffer than that of beam theory.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.122-133
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• 1999

Overlap, excessive wide gaps, and errors between blocks during erection process increases cost and man-hour. In this paper, a system to simulate the assembly process is suggested and a plane block assembly of welding deformation with gravity is simulated in consideration of assembly order, deformations and errors occurring in the cutting and forming processes are not considered and welding deformations are acquired by equivalent stiffness and load method from experiments and hull double bottom plane block is assembled on a assembly order by panel method. It is certified that according to the order of assembly, intermediate product shape affects rigidity which affects welding deformations. Assembly order must be considered in the assembly process. It is certified that the gravity has important role in the assembly process.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.5
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• pp.169-178
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• 2008

Compressive flanges of steel box girder is designed based on the ultimate strength behavior of sub-panel which is enclosed with longitudinal stiffeners and transverse stiffeners on appropriate safety factor. However, it is rational that the ultimate strength is calculated considering the various factors such as number and stiffness of longitudinal stiffener, spacing of transverse stiffener, initial deformation and residual stress distribution. In this study, an analysis program based on Folded Plate theory is developed considering the geometric effects and the material nonlinearity. The analysis program is applicated to the steel box girder bridges which is really constructed in domestic.

• Journal of the Korea Institute of Building Construction
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• v.23 no.3
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• pp.295-303
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• 2023

South Korea has recently witnessed an increasing number of seismic events, leading to a surge in studies focusing on seismic earth pressures, as well as the attributes of geological layers and ground where foundations are established. Consequently, earthquake-resistant design has become imperative to ensure the safety of subterranean structures. The slurry wall method, due to its superior wall rigidity, excellent water resistance, and minimal noise and vibration, is often employed in constructing high-rise buildings in urban areas. However, given the separation between panels that constitute the wall, slurry walls possess limited resistance to seismic loads in the longitudinal direction. As a solution, several studies have probed into the possibility of interconnecting slurry wall panels to augment their seismic performance. In this research, we developed and evaluated a method for linking slurry wall panels using mechanical joints, including concrete-confined steel pipes and headed bars, through mock-up tests. We also assessed the constructability of the suggested method and compared it with other analogous methods. Any challenges identified during the mock-up test were discussed to guide future research in resolving them. The results of this study aid in enhancing the seismic performance of slurry walls through the development of an interconnected panel method. Further research can build on these findings to address the identified issues and improve the efficacy and reliability of the proposed method.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.78-86
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• 2019

This paper describes the stiffness optimization of the torsion spring hinge of the large SAR antenna considering the deployment performance. A large SAR antenna is folded in a launch environment and then unfolded when performing a mission in orbit. Under these conditions, it is very important to find the proper stiffness of the torsion spring hinge so that the antenna panels can be deployed with minimal impact in a given time. If the torsion spring stiffness is high, a large impact load at the time of full deployment damages the structure. If it is weak, it cannot guarantee full deployment due to the deployment resistance. A multi-body dynamics analysis model was developed to solve this problem using RecurDyn and the development performance were predicted in terms of: development time, latching force, and torque margin through deployment analysis. In order to find the optimum torsion spring stiffness, the deployment performance was approximated by the response surface method (RSM) and the optimal design was performed to derive the appropriate stiffness value of the rotating springs.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.171-178
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• 2023

In this paper, we propose a smart automated warehouse to maximize space utilization. Previous elevator-type automatic warehouses were designed with a maximum payload of 100kg on trays, which has the problem of extremely limiting the number of pallets that can be loaded within the space. In this paper, we design a smart warehouse that can maximize space utilization with a maximum vertical stiffness of 300kg. As a result of the performance evaluation of the implemented warehouse, the maximum payload was 500.6kg, which satisfied the original design and requirements, the lifting speed was 0.5m/s, the operating noise of the device was 67.1dB, the receiving and forwarding time of the pallet was 36.92sec, the deflection amount was 4mm, and excellent performance was confirmed in all evaluation items. In addition, the PLC control method, which designs the control UI and control panel separately, was integrated into the PC system to improve interoperability and maintainability with various process management systems. In the future, we plan to develop it into a fully automatic smart warehouse by linking IoT sensor-based logistics robots.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.956-959
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• 2007

기존 투명방음판용 알루미늄 프레임의 구조적 단점을 보완할 수 있는 강재-FRP(Fiber Reinforced Plastic) 합성단면 구조재를 개발하였으며, 아울러 조립이 간편하고 외부 충격에 의해 쉽게 분리가 되지 않는 삽입형 수평재-수직재 코너연결부 상세를 개발하였다. 개발된 강재-FRP 합성단면 구조재와 코너연결재를 결합하여 프레임을 형성하고 그 사이에 투명패널을 삽입함으로써 길이 4m, 높이 1m 투명방음판 시작품을 완성하였으며, 이렇게 완성된 투명방음판 시작품을 대상으로 KS 4770-1 구조성능 평가시험을 수행하였다. 한국도로공사 교량부 시험하중에 대해 설계된 강재-FRP 합성단면 프레임 투명방음판의 구조성능 평가결과, FRP 의 추가적인 구조강성 증가 효과로 인해 한국도로공사 교량부 시험하중을 약간 상회하는 KS 2 호 등급시험하중까지도 만족시키고 있음을 확인할 수 있었다.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.89-90
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• 2017

본 논문에서는 일사량 데이터를 이용한 태양광 부스트 컨버터의 MPPT 성능분석에 대한 연구를 제안한다. 실외 실험을 통해 일사계(Pyranometer)로 측정한 일사량 데이터와 그에 따른 태양광 패널의 출력 데이터를 검토하여 부스트 컨버터의 MPPT 성능을 테스트 하였으며, 측정한 일사량 데이터를 토대로 수행한 시뮬레이션과 실험결과를 비교 분석하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.202-209
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• 2007

Vehicle body frame stiffness affects the dynamic and static characteristics. Vehicle frame structural performance is greatly affected by crossmember and joint design. While the structural characteristics of these joints vary widely, there is no known tool currently in use that quickly predicts joint stiffness early in design cycle. This paper presents the joint design factors affecting on low frequency vibration. The joint factors are joint panel thickness, section property, flange width and weld point space. To study the effect on vehicle low frequency vibration, case studies for these factors are performed. And Sensitivity analysis for section property is performed. The result can present design guide for high-stiffness vehicle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.177-184
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• 2008

Vehicle body frame stiffness affects the dynamic and static characteristics. Vehicle frame structure performance is greatly affected by crossmember and joint design. While the structural characteristic of these joint vary widely, there is no known tool currently in use that quickly predicts joint stiffness early in design cycle. This paper present the joint design factors affecting on low frequency vibration. The joint factors are joint panel thickness, flange width and weld point space. To study the effect on vehicle low frequency vibration, case studies for these factors are performed. The result can present design guide for high-stiffness vehicle.