• Computational Structural Engineering
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• v.17 no.1
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• pp.15-24
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• 2004

첨단 산업 시대에 도래하면서 재료와 화학 공학의 눈부신 발전에 힘입어 각종 구조용 신소재인 복합재료가 등장하게 되었고, 많은 공학 분야에 활발히 적용되었다. 최근들어 건설 산업에 복합재료의 일종인 FRP(Fiber Reinforced Plastics)재료를 철골 부재와 같은 얇은 판, 개단면의 형태인 박벽 복합재료를 사용하려는 노력들이 진행되어 왔다. 따라서 건설 분야의 기술자들은 박벽 복합재료의 해석 및 설계 기술력과 산업화 활용에 대해 관심을 갖게 되었다.(중략)

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.1
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• pp.11-21
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• 1998

During an earthquake, there are three main components of excitation : horizontal excitation of the ground, vertical excitation of the pile due to superstructure feedback produced by vertical excitation of the ground, and the seawater excitation induced by the vertical ground shaking, that is, "the seaquake." These excitations could have effects on the soil plugs in open-ended pie piles installed at offshore sites. In this study, seaquake excitation induced by the vertical ground shaking was simulated by pulsing the water pressure at the seabed. During a seaquake, due to the induced excess porewater pressure and pressure gradients in the soil, the capacity of open-ended pipe piles installed in a simulated sea depth of greate than 220 m was reduced serevely and the soil plugging resistance was degraded by more than 80% The soil plug was failed because of eh upward seepage forces that developed in the soil plug due to excess pore water pressure produced in the bottom of the soil plug during the seaquake, The compressive capacity of ar open-ended pile in a simulated sea depth of less than 220 m was reduced only by about 10% and the soil plug resistance was degraded by less than 5%.s than 5%.

• Journal of Korean Society of Steel Construction
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• v.14 no.1
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• pp.41-49
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• 2002

An efficient algorithm automatically determining cross sectional properties of thin-walled beams is developed using the minimum information about geometry of the cross section. This scheme is applied to automatic calculation of normal and shear stress distribution corresponding to stress resultants as well as sectional constants for complex open and closed thin-walled sections. Numerical examples evaluating section constants and stress distributions is presented and compared with the available reference's results.

• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.605-615
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• 2014

The purpose of this study is to propose an economic new type rib by applying plate stiffening methods of the corrugated plate and the honey-comb sandwich panel to the steel deck plate and comparing the new type rib with existing open and closed ribs. The trapezoidal corrugated type, ㄹ type, honey-comb type and ㅁ type ribs are considered as new type ribs and the moment and the steel volume are compared with that of open ribs and closed ribs. The results shows that the honey-comb type and ㅁ type ribs are good in aspects of economic feasibility and the ㅁ type is better than the honey-comb type. To make the ㅁ type rib applicable to the steel deck plate, the sensitivity analysis and parametric study are performed and the system to select the proper section under the particular stress condition is established. The closed rib of real bridges is compared with the ㅁ type rib of the proposed system and it is known that the new type rib is more economic. Therefore, more economic steel deck plates can be achieved by using the system proposed in this study for the plate stiffened with the new ㅁ type rib.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.101-108
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• 2012

The orthotropic steel deck bridge made by using relatively thin steel plate, and structural members such as transverse and longitudinal ribs, cross beam, etc. in the bridge are fabricated with complex shape by welding. Therefore, the possibility occurring deformation and defects by welding is very high, and stress states in the welded connection parts are very complex. Also, the fatigue cracks in orthotropic steel deck bridge are happening fromthe welded connection parts of secondary member than main member. However, stress evaluation for main members is mainly carried out in the design process of the bridge, detailed stress evaluation and characteristic analysis is not almost reviewed in the structural details which fatigue crack occurred. For the orthotropic steel deck bridge with open ribs which has been serviced for 29 years, in this study, the cause of fatigue crack is investigated and the fatigue safety of the bridge is examined based on fieldmeasurement by the loading test and real traffic condition. Also, structural analyses using gridmodel and detailed analysis model were carried out for the welded connection parts of longitudinal rib and diaphramthat fatigue crack occurred. Additionally, the behavior characteristics due to running vehicles were investigated by using influence area analysis for these structural details, and the occurrence causes of fatigue crack in the target bridge were clarified.

• Geotechnical Engineering
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• v.9 no.3
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• pp.23-34
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• 1993

Model pile teats, using large calibration chamber in which the stress state and the relative density can be controlled, were performed in order to study on the effect of soil condition on the behavior of open-ended steel pipe pile. The model pipe pile was made up of two pipes to separately measure each component of bearing capacity of open -ended steel pipe pile. According to the tests results, pile plugging and driving resistance of the pile installed in sand were primarily dependent on the horizontal stress and the relative density. Plug bearing capacity, outside skin fricition and total bearing capacity were also mainly dependent on the horizontal stress and relative density. Moreover, the ratio of the horizontal stress acting on the outside wall of open -ended pipe pile after installation to the original horizontal stress was not nearly affected by original value of horizontal stress. It is bigger than one in the case of dense deposit, equal to one for medium deposit, and smaller than one for very loose deposit. It seems to be mainly dependent on the relative density for a given soil.

• Computational Structural Engineering
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• v.9 no.4
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• pp.135-140
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• 1996

Single angle or channel with thin-walled open section can be used as compression member for example as web member in truss. In this case the inevitable eccentricity due to fabrication is commonly neglected in structural design. However eccentricity effect should be considered in the member design, especially in case of compression member. The critical loads of compression members that buckle by twisting or by a combination of bending and twisting are to be determined by solving governing differential equations. In this paper, the investigations are limited to the rolled channels([), equal-leg angles(L), lipped channels(C) and the applied loads are assumed to have some eccentricities.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.2
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• pp.105-113
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• 1999

This paper resents a prediction method of natural frequencies of coupled horizontal and torsional vibration of hull girder based on design sensitivity analysis in case of the changes of system parameters. The sensitivity analysis is formulated applying the direct differentiation method and transfer matrix method. In the analysis, warping, shear deformation due to torsion and the continuity condition at the connected part of open and closed hull section are considered. Using the presented method. The affection for natural frequencies by the change of system parameters, especially cargo and added mass and their centers, is numerically investigated for a real large container carrier.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.43-50
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• 2000

In the first-order shear deformation laminated beam theory (FSDT), the Kirchhoff hypothesis is relaxed such that the transverse normals do not remain perpendicular to the midsurface after deformation. Bending behavior of laminated composite thin-walled beams with singly- and doubly-symmetric open sections under uniformly distributed and concentrated loads is analyzed by the Timoshenko-type thin-walled beam theory. A closed-form expression for the shear correction factor of I-shaped composite laminated section is obtained. Numerical examples are presented to compare present analytical solutions by FSDT with the finite element solutions obtained by using three dimensional model. The effects of lamination of scheme and length-to-height ratio on the shear deformation of laminated composite beams with various boundary conditions are studied.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.51-58
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• 2000

Lateral buckling behavior of laminated composite thin-walled I-section beams subjected to bending moment is investigated by applying the nonlinear anisotropic thin-walled beam theory. The constituent laminated thin-walled elements of I-section are assumed to be symmetrically laminated. The bending, twisting, and warping stiffnesses of the cross section are obtained based on the definitions of these stiffnesses In the thin-walled anisotropic beam theory In numerical examples, singly-symmetric I-beams with specially orthotropic, quasi-isotropic, angle-plys and various boundary conditions are considered. To validate the proposed theoretical approach, present analytical solutions are compared with three dimensional finite element solutions.