• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.63-72
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• 2007

As business of steel consuming industries is freshly booming in domestic and foreign countries especially in China, the price of steel plates comes to very high compare with the other materials. The HR Plates made from hot rolled coils is lower steel plates in price. In this study, material characteristics of HR Plates is investigated and availabilities of HR Plates for steel bridges as sub member or a main member is discussed. No difference between steel plates and HR Plates with thickness up to 22mm is found in most characters such as cutting operation, fabrication and even welding. As sub member in steel box girders, the application ratio and the loss ratio of HR Plate is investigated as about $10{\sim}15%$, average $10{\sim}15%$ respectively.

• Journal of Korean Society of Steel Construction
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• v.15 no.2
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• pp.159-165
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• 2003

A tubular member with through-gusset plate is often used to transmit axial compression in an electric transmission towers. In current code, the strength of tubular member is evaluated with an effective length factor k=0.9 without considering the deformation of boundary element. A buckling strength of member with end gusset plate is affected by stiffness ratio($\beta$) and the length ratio(G) between main tubular member and end gusset plate. In this study theoretical mechanism based on the elastic buckling behavior was investigated, and finite element analysis was performed to propose a formula for the buckling strength and effective length factor of tubular member in elsatic and inelastic ranges.

• KCI Concrete Journal
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• v.12 no.2
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• pp.55-72
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• 2000

This paper proposes a mechanical model to describe the load-deformation responses of the reinforced concrete plate members under service load state. An Analytical method is introduced on the basis of the rotating crack model which considers equilibrium, compatibility conditions, load-strain relationship of cracked member, and constitutive law for materials. The tension stiffening effect in reinforced concrete structures is taken into account by the average tensile stress-strain relationship from the load-strain relationship for the cracked member and the constitutive law for material. The strain compatibility is used to find out the crack direction because the crack direction is an unknown variable in the equilibrium and compatibility conditions. The proposed theory is verified by the numerous experimental data such as the crack direction, moment-steel strain relationship, moment-crack width relationship. The present paper can provide some basis for the provision of the definition of serviceability for plate structures of which reinforcements are deviated from the principal stresses, because the present code defines the serviceability by the deflection, crack control, vibration and fatigue basically for the skeletal members. The proposed theory is applicable to predict the service load state behavior of a variety of reinforced concrete plate structures such as skew slab bridges, the deck of skew girder bridges.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.69-75
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• 2017

Structural safety evaluation for static strength of thin plate RC member with high strength concrete is conducted in this study. Static strengths were predicted and compared with the experimental values. Predicted values were calculated by the evaluation formula based on the punching shear behavior and the yield line theory which can appear in the plate members. Static load tests were carried out for the specimens with high strength concrete and the test results were compared with the required performance in design. The comparison results show that the specimens with high strength concrete have sufficient structural safety for flexural and punching shear performance required in design. High strength concrete specimens exhibited excellent strength despite their small thickness. The range of concrete strengths applied in this study was about 60 MPa to 100 MPa.

• Journal of Korean Society of Steel Construction
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• v.26 no.6
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• pp.571-579
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• 2014

The steel braces are used to control the lateral drift of high rise buildings. The braces are designed as tensile members since the braces consisted of slender member can not resist compressive loads by elastic buckling. To resolve this problem, a lot of research were performed to develop the non-buckling member. The force limiting device (FLD.) is one of them. The purpose of this study is the development of FLD. to prevent a elastic buckling for a slender member. The folded plate type is proposed to induce the yielding before occurring elastic buckling. In this study, member test and FEM analysis for proposed type were performed. Further, It is verified that the structure with FLD member is stable by high energy absorption. The proposed folded plate type FLD could be effective to preserve the compressive member from the elastic buckling.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.94-101
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• 1999

There are two methods commonly used in design of splice plate connection of frame structure. The one is Design by Actual Stress which can sufficiently transfer actual force to an adjacent member using rows of bolts. The other is Design by Member Strength which is able to transfer total allowable stress of effective section area to a connected member. In real design, as a matter of convenience, Standard Connection Drawings have used according to Design by Member Strength. But this method underestimate connection force in shear connection where large connection moment occured. In this study, these Design methods are compared by connection moment in shear connections. and the adequate use of them are recommended. Also In order to evaluate more accurately the actual stress of splice plate of flange on moment. connection, a new calculation method of it is recommended.

• Structural Engineering and Mechanics
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• v.34 no.2
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• pp.247-275
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• 2010

In this study, experimental, numerical, and analytical approaches were carried out to evaluate the behavior and prestressing effect of prestressed composite beam by external tendon and cover plate. Behavior of prestressed composite beam, load-carrying capacity, effects of prestressing, and ultimate strength were estimated. The contribution of the section increase of the prestressing method using tendon was less than the prestressing method using cover plate. In accordance with numerical and analytical approaches, the ultimate strength of the prestressed composite beam is shown to be the same value because strength is determined according to the plastic resistance moment and the plastic neutral axis; however, both plastic resistance moment and neutral axis are not affected by prestressing force but affected by sectional stiffness of the prestressing member. Based on these approaches, we concluded that the prestressing method using tendon can be useful in applications without an increase in self-weight, and the prestressing method using high-strength cover plate can be applied to reduce the deflection of the composite beam. The prestressing method using high-strength cover plate can also be used to induce prestress of the composite beam in the case of a large deflection due to a smaller sectional stiffness of the composite beam.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.554-562
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• 2007

To increase the demand of HR Plate with thickness up to 22mm, it is necessary that HR Plate is applicable to full member in steel bridge including main girder. In this study, availabilities of the narrow steel box girder of light railway transit with HR Plate width as a main member are discussed. Computational analysis is performed in 15 bridge models of light railway transit with beam element and plate element. As an analysis results, three models in tight railway transit are presented. In conclusion, it is validated that HR Plate can be applying to narrow steel box girder in the light railway transit.

• Journal of Information Display
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• v.8 no.1
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• pp.18-21
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• 2007

We developed a new configuration of polarized light out-coupling lightguide plate (LGP) in the LCD backlight. By collimating the light into the LGP, one linear polarization component experienced total internal reflection at the planar interface of LGP and anisotropic layer, whereas the orthogonal polarization was out-coupled along the normal direction through a birefringent layer and subsequent isotropic microstructures.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.408-413
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• 2004

High speed planning boats also have been required more and more the rational strength analysis and evaluation for the optimal structural design in respect of the structural lightness according to the high speed trend. Even though the suggestion of the simple type equation for the equivalent dynamic pressure is reasonable to design the scantling of ship structure conveniently, many research activities for more reasonable improvement of the simple design pressure, have been continued to suggest the more accurate equivalent static description of tire structural response such as the deflection and stress of hull structure. In this research, we focus on the aluminum bottom stiffened plate structure in which structural scantling is mainly depend on the local loads such as dynamic or impact pressure without other load effects and structural response for the simple dynamic equivalent pressure was investigated through the structural analysis. In order to investigate the structural response of the bottom stiffened plate structure subjected to the dynamic equivalent design pressure, linear and nonlinear structural analysis of the bottom stiffened plate structure of 4.3 ton aluminum planning boat was performed based on the equivalent static applied loads which were derived from the KR regulation and representative one among various dynamic equivalent pressure equations. From above analysis results, we found that the response such as deflection and stress of plate member was similar with the response results of one plate member model with fixed boundary, which was published previous paper and in case of KR design loading, all response of stiffened plate structure were within elastic limit. Through the nonlinear analysis, nearly elastic behavior including the slight geometrical nonlinear response was dominant but plastic local zone was appeared at $85\%$ limit load. Therefore, we can say that through tire linear and nonlinear analysis, this stiffened plate member has no structural strength problem based on the yield criteria in case within $60\%$ limit load except the other strength point of view such as the fatigue and buckling problem.