• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.435-442
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• 2001

Derivation procedures of exact dynamic element stiffness matrix of shear deformable nonsymmetric thin-walled straight beams are rigorously presented for the spatial free vibration analysis. An exact dynamic element stiffness matrix is established from governing equations for a uniform beam element with nonsymmetric thin-walled cross section. First this numerical technique is accomplished via a generalized linear eigenvalue problem by introducing 14 displacement parameters and a system of linear algebraic equations with complex matrices. Thus, the displacement functions of dispalcement parameters are exactly derived and finally exact stiffness matrices are determined using member force-displacement relationships. The natural frequencies are evaluated and compared with analytic solutions or results of the analysis using ABAQUS' shell elements for the thin-walled straight beam structure in order to demonstrate the validity of this study.

• Structural Engineering and Mechanics
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• v.44 no.4
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• pp.539-569
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• 2012

The behaviour of beam-to-column connections plays an important role in the analysis and design of steel structures. A computer-based method is presented for nonlinear steel frames with semi-rigid connections accounting for shear deformations. The analytical procedure employs transcendental stability functions to model the effect of axial force on the stiffness of members. The member stiffness matrix, and the fixed end forces for various loads were found. The nonlinear analysis method is applied for three planar steel structures. The method is readily implemented on a computer using matrix structural analysis techniques and is applicable for the efficient nonlinear analysis of frameworks.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.297-300
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• 2010

본 논문에서는 일반적인 해석, 시공단계를 고려한 해석, 시공단계와 장기거동을 고려한 해석의 3가지 해석방법을 사용하여 수평부재의 설계에 적합한 해석방법을 제안하였다. 80층의 2D 구조모델에 3가지 해석방법을 적용하여 각 해석방법에 따라 부등축소량, 수직부재에 작용하는 축력, 수평부재의 단부에 작용하는 내력의 해석결과를 얻어 비교하였다. 또한 부재의 내부에서 철근과 콘크리트의 하중분담율의 시간에 따른 변화양상을 알아보았다. 해석결과 시공단계에 의한 영향은 수평부재에 작용하는 축력과 부등축소량 예측, 부재 내력 해석에 있어서 반드시 고려되어야 함을 알 수 있었다. 장기거동의 효과는 기둥축소에는 크게 영향을 미치지만 수직부재의 축력, 수평부재의 내력에는 변형만큼의 영향은 보이지 않는다. 시공시의 보정량을 결정하기 위해서는 장기거동이 반드시 고려되어야 하지만 부재의 단면설계의 목적으로는 제외되어도 무방할 것으로 판단된다.

• Structural Engineering and Mechanics
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• v.7 no.3
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• pp.319-330
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• 1999

The design of composite space trusses is a demanding task that involves taking several decisions on the truss depth, number of panels, member configuration, number of chord layers and concrete slab thickness and grade. The focus in this paper is on the design of top concrete slabs of composite space trusses, and in particular their thickness. Several effects must be considered in the process of designing the slab before an optimum thickness can be chosen. These effects include the inplane forces arising from shear interaction with the steel sub-truss and the flexural. and sheer effects of direct lateral slab loading. They also include a constructional consideration that the thickness must allow for sufficient cover and adequate space for placing the reinforcement. The work presented in this paper shows that the structural requirements on the concrete slab thickness are in many cases insignificant compared with the constructional requirements.

• Advances in Computational Design
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• v.1 no.1
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• pp.105-117
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• 2016

The objective of this work is to study the restraining effect in fire resistance of framed structures and to evaluate the global response of reinforced concrete frames when exposed to fire based on advanced finite element method. To study the response a single portal frame is analyzed. The effect of floor slab on this frame is studied by modeling a beam-column-slab assembly. The evolution of temperature distribution, internal stresses and deformations of the frame subjected to ISO 834 standard fire curve for both the frames are studied. The thermal and structural responses are evaluated and a comparison of results of individual members and entire structure is done. From the study it can be seen that restraining forces has significant influence on both stresses and deflection and overall response of the structure when compared to individual structural member. Among the various structural elements, columns are the critical members in fire and failure of column causes the failure of entire structure. The fire rating of various structural elements of the frame is determined by various failure criteria and is compared with IS456 2000 tabulated fire rating.

• Journal of the Korean Society of Safety
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• v.34 no.2
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• pp.34-39
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• 2019

Vinyl house consists of main rafter, lateral member, clamps and polyethylene film. Many vinyl houses are used in the countryside to grow vegetables. These vinyl houses have occasionally been collapsed due to heavy snowfall in winter. Many farmers get a lot of economical damages, if vinyl houses are collapsed. So it is most important to built a safe vinyl house that can withstand heavy snowfall. In this study, a structural analysis was performed on three types of vinyl houses(07-single-01, 10-single-04, 12-single-01). In addition, the structural analysis of the three types of vinyl houses provided axial forces, flexural moment, and combined stress. For these three types of vinyl houses, structural safety was reviewed by obtaining the combined stress ratio by the strength design method. This structural review showed that the specifications for the vinyl house proposed in the design are not safe. Especially, the result of increasing the design snow load by 15 percent and 30 percent showed that the vinyl house structure constructed as a standard for vinyl house was a more dangerous structure. Therefore, it is necessary to revise regulations such as increasing the thickness of rafters or widening the gap in order to make vinyl houses structurally safe for heavy snowfall in the future, and to devise diverse methods to make vinyl houses that are structurally safe.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.50-56
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• 2017

The perimeter structure in high-rise buildings, which plays a major role in resisting lateral forces, is generally formed by the orthogonal placement of the beam and column, but currently various grid patterns are implemented. In a previous study, the adaptability of the $IsoTruss^{(R)}$ grid (ITG) as a perimeter structure was examined. In this study, a method of estimating the required cross sectional area of a member in a preliminary design is proposed. The members of the perimeter structure are placed in three planes, perpendicular (PPR), parallel (PPL) and oblique (POQ) to the lateral loading, and the stiffness of the members in the POQ was taken into account by projecting them onto the PPL or PPR. Three models are established for member size zoning through the height of the building, in order to investigate the effect of the shear and moment in the calculation of the required cross sectional area. To examine the effectiveness of this study, a 64-story building is designed and analyzed. The effect of the member size zoning was examined by comparing the maximum lateral displacement, required steel amount, and axial strength ratio of the columns. Judging from the maximum lateral displacement, which was 97.3% of the allowable limit, the proposed formula seems to be implemental in sizing the members of an ITG structure at the initial stage of member selection.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.547-559
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• 2012

The concrete structural design in domestic has based on the allowable stress design (ASD) method and ultimate strength design (USD) method. Recently limit state design (LSD) method has issued and attempted to adopt in geotechnical design. Because ASD method and USD method have restriction in economic design. In this study, the generated member forces were calculated about high strength concrete segment lining based on japanese LSD code. And it compared with domestic USD code for identifying the economic design possibility of LSD and domestic applicability. In analysis results, the aspect of moment had generated similarly each other but the member forces of japanese LSD code were decreased (26.0% of moment and 26.7% of shear force) comparing with USD method. For that reason, possibility of economic segment design with stable condition were identified.

• Steel and Composite Structures
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• v.17 no.3
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• pp.253-269
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• 2014

Among the various alternatives to make a steel tubular member connection, making a slotted and gusset plate welded connection is one of the most frequently preferred alternatives. This type of connection is essentially an end connection that is made by slotting the tube longitudinally, inserting the gusset plate and then placing longitudinal fillet welds at the tube-to-plate interface. In this paper an experimental study on the behaviour of such connections in stainless steel is presented. 24 specimens were tested under concentrically applied axial tensile forces for varying tube-to-gusset plate weld lengths. Both circular and box section members were considered in the test program. Load-deformation curves were obtained and comparisons were made in terms of strength and ductility. The results obtained from the study were then critically examined and compared with currently available design guidance for slotted gusset plate welded tubular end connections. It is noted that no specific rules exist in international specifications on structural stainless steel which cover the design of such connections. Therefore, the results of this study are compared with the existing design rules for carbon steel.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.361-364
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• 2008

This study was performed to estimate the anchorage behavior for Bi Prestressed Concrete Girder(Bicon girder) which could introduce effectively prestressed forces into concrete girders. A bicon girder is manufactured by means of introducing pure bending moment that prestress simultaneously the compressive member(steel bar) and the tensile member(steel tendon). Therefore, the steel bar and the steel tendon must be unified in both ends and compressive and tensile force be offset. Anchorage dimension of 6 test specimens was designed under PTI specification which defined maximum stress and deformation to estimate structural behavior. Test results showed that the stress and the deformation of anchorage were within limits if the steel bar behaviored elastically.