• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.357-367
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• 2006

Drift design methods using resizing algorithms have been presented as a practical drift design method since the resizing algorithms proposed easily find drift contribution of each member, called member displacement participation factor, to lateral drift to be designed without calculation of sensitivity coefficient or re-analysis. Weight of material to be redistributed for minimization of the lateral drift is determined according to the member displacement participation factors. However, resizing algorithms based on energy theorem must consider loading conditions because they have different displacement contribution according to different loading conditions. Furthermore, to improve practicality of resizing algorithms, structural member grouping is required in application of resizing algorithms to drift control of high-rise buildings. In this study, three resizing algorithms on considering load condition and structural member grouping are developed and applied to drift design of a 20-story steel-frame shear-wall structure and a 50-story frame shear-wall system with outriggers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.237-243
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• 2012

The thickness optimization of the gearbox housing for 5MW wind turbine is carried out with the help of the efficient structure analysis model and the approximation model of objective function. Wind turbine gearbox is a complex structural system composed of a number of gear trains, shafts, bearing and gearbox housing, requiring a tremendous number of elements for the structural analysis and design. In this paper, an effective analysis and design model considering the tooth stiffness of helical gears is proposed. It enables to significantly reduce the total element number and the analysis time. Through the numerical optimization of housing thickness making use of the effective gearbox model and the approximate model of objective function, the total weight of the gearbox housing is minimized. It has been observed from the numerical experiment that the approximation model is reliable and the optimization result is acceptable and verified analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.4
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• pp.365-373
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• 2008

Fiber Reinforced Polymer, FRP has a light weight, a high tensile strength based on design, non-electronic, non-magnetic, and rust-resistant feature, etc and many researches are being conducted recently on FRP in the construction area. Among them, GFRP (Glass Fiber Reinforced Polymer) is excellent in price competitiveness and is widely being used. However, since GFRP has a relative low modulus of elasticity and causes excessive deflection, the section must be large to be used as a structural component and an investigative review must be carried out in design to set the limit for deflection by the use load. Therefore, in order to solve the mentioned technical problems, this study suggested a section of a module form such that application of a large-scale section is possible. Also, to secure the low rigidity of FRP, this study developed a new FRP+ concrete composite girder form that confined the concrete. To identify the structural movement of the developed FRP+ concrete composite girder, shear strength test was carried out.

• Composites Research
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• v.26 no.2
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• pp.105-110
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• 2013

In this study, we suggest the new floating PV generation structure which is improved the structural and economical efficiency compared with the system developed in the previous research. Pultruded FRP has superior physical and chemical material properties compared with those of conventional structural materials. Especially, pultruded FRP has an excellent corrosion-resistance, light-weight, and it also has high specific strength and stiffness which are highly appreciated for the design and fabrication of floating PV generation structure under harsh environmental condition. In this study, structural analysis using the finite element method has been performed to investigate the safety of new floating PV generation structure and newly applied structural members.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.89-97
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• 2013

With regard to complex-shaped tall buildings whose plans and constructions have been gradually on the increase, this study was aimed to analyze their structural behaviors during construction by applications of construction sequences analyses to prototype models. For twisted tall buildings, total 18 models of with three conditions of a lateral load-resisting system, a twisting angle, and a construction method were selected. A diagrid system and a braced tube system were applied as a lateral load-resisting system. For each lateral load-resisting system, three types of plan with $0^{\circ}$, $1^{\circ}$, and $2^{\circ}$ twisting angles and three construction methods with construction sequences of exterior tube and interior frame were assumed. The structural performances of tall buildings under constructions were analyzed with results of lateral displacements from construction sequence analyses. Also, construction performances of the construction period and the maximum lift weight were compared.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.5
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• pp.697-702
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• 2010

A WIG(Wing-In-Ground effect) craft flies close to the water surface by utilizing a cushion of relatively high pressurized air between its wing and water surface. This implies that when one designs such craft it is important to have lightweight structures with adequate strength to resist external loads with some margins. To investigate this requirement, this paper deals with the structural analysis of the bottom plate of small WIG craft having a design landing weight of 1.2-ton. As building materials for the WIG craft, pre-preg carbon/epoxy composites are considered. The strength information of the bottom plate is obtained using the first-ply-failure analysis in conjunction with a mid-plane symmetric laminated plate theory. As a result, the first-ply-failure location, load and deflection of the bottom plate are obtained. The calculated strength information is compared with the water reaction load for the bottom plate of seaplanes considered when they land on the water surface -the same fluid-structure interaction mechanism as that of WIG craft. In the calculation of seaplane water reaction load information, the rules shown in FAR(Federal Aviation Regulations) Part 25 are used. Through the comparison, the structural integrity of the bottom plate for the WIG craft is checked.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.165-170
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• 2019

This study carried out the structural analysis and vibration analysis on scooter seat. By comparing with three kinds of B-bone A, Julio B, and City Ace C, the load was applied to scooter seat as much as a weight of person. Through structural analysis, this study examined which seat is most deformed by comparing the deformation each other or affords passengers most convenience and does not afford passengers the inconvenience by absorbing the vibration during driving. Model C has the most total deformation at the structural analysis result and Model B is seen to be changed to be convenient to sit the deformation as it deforms largely. Through this study, which seat is most convenient and becomes strong on durability can be confirmed. As the durability analysis result data of scooter seat model obtained on the basis of this study result are utilized, the esthetic sense can be shown by being grafted onto the machine or structure at real life.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.80-85
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• 2021

In the fourth industrial revolution, the demand for metal three-dimensional (3D) printing technology is rapidly increasing. Metal 3D printing is an efficient method for manufacturing products because the method reduces material waste compared to subtractive manufacturing. In addition, products with complex shapes, such as turbine blades, can be easily produced using metal 3D printing because the method offers a high degree of freedom. However, due to the long production time of metal 3D printing, mass production is impossible, and post-processing is necessary due to its low precision. Therefore, it is necessary to develop a new hybrid process that can efficiently process metals and to develop a metal 3D-printing-based hybrid processing system technology to secure high processing precision and manufacture complex shapes. In this study, the structural stability of a metal 3D printer based hybrid machining center was analyzed through structural analysis before its development. In addition, we proposed a design modification that can reduce the weight and increase the stiffness of the hybrid machining center by performing shape lightning based on the structural analysis results.

• Analytical Science and Technology
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• v.21 no.4
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• pp.245-258
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• 2008

Five triterpenic acids as marker compounds were extracted and isolated from Prunellae Spica by column chromatography and reversed-phase high-performance liquid chromatography (HPLC), and their purity was determinated by HPLC (purity ${\geq}90%$). Molecular weight and elemental compositions of the five marker compounds were determined by fast atom bombardment high-resolution mass spectrometry (FAB-HRMS). The structural determination of the five marker compounds was carried out fast atom bombardment collision-induced dissociation tandem mass spectrometry (FAB-CID-MS/MS). The collision-induced dissociation (CID) of protonated molecules $[M+H]^+$ and deprotonated molecules $[M-H]^-$ produced diverse product ions due mainly to retro Diels-Alder reaction (RDA), dehydration and decarboxylation. Moreover, the CID-MS/MS spectra of the $[M-H]^-$ ions were observed charge-remote fragmentation (CRF) patterns. On the basis of interpretation of CID-MS/MS spectra, structural elucidation of triterpenic acids isolated from Prunellae Spica was clearly performed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.97-107
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• 2006

This study is structural analysis and continuous, discrete optimum design of braced steel frame structures under earthquake loads considering soil condition. The program which is able to perform simultaneously structural analysis and continuous, discrete optimum design, it is applied steel frame structures using unbraced, Z-braced, and X-braced types and analyze the program about static loads and seismic loads. The purpose of this study is to present proper braced type for seismic effects by comparing and analyzing results of analytic method about various cases using specially Newmark-Hall design spectrum, ATC design spectrum and ATC equivalent static analysis and finding minimum weight and design variables which satisfy the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06 and various constraints.