• Journal of Korean Society of Steel Construction
• /
• v.12 no.1 s.44
• /
• pp.1-8
• /
• 2000

In this study, the effect of semi-rigid connections on the structural behavior of 20-story braced steel structure has been investigated utilizing the second-order elastic structural analysis program in which nonlinear behavior of beam-column connections and geometric nonlinearity have been considered. Global effects such as P-delta effect and sway at the top have been studied, as well as distribution of member force and combined stress in structural members as local effects. When the structure subjected to horizontal load and vertical load is equipped with lateral-load resisting system such as braces, replacement of shear connection with semi-rigid connection has not caused any problem in P-delta effect and top lateral displacement. Distribution of member forces resulted in reduction in member size for economic structural design.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.1
• /
• pp.101-108
• /
• 2012

Initial shape analysis for cable-stayed bridges should be able to find optimizated initial cable forces and unstrained length that minimize deflection and bending moments of the deck and pylon. Comparison study of an improved initial force method and TCUD method for determination of initial cable forces in cable-stayed bridges is presented in this paper. For this purpose, an elastic catenary cable element and a nonlinear frame element are firstly described. And concepts and algorithm of two analysis methods are then presented. Finally to demonstrate the validity and the accuracy of two methods, numerical examples for initial state problems of cable-stayed bridges are given and compared based on these methods.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.24 no.5
• /
• pp.473-480
• /
• 2011

Recently, the resizing algorithms based on the displacement participation factors have been developed for sizing members to satisfy stiffness criteria. It is proved that this resizing algorithms made for utilizing worker's stiffness design are practical and rational due to the simplicity and convenience of the method. The resizing algorithm can be practically and effectively applied to drift design of buildings. However, the researches on the change of inelastic behavior by the resizing algorithm has been insufficient. To identify the effect on the inelastic behavior of buildings by the resizing method, this study used the reinforced concrete shear wall-frame example. Through the application of the resizing method, the weights of shear wall in the lower class and the weights of columns and beams in the upper class increased respectively. And the initial stiffness of the building increased and the ductility of the buildings had similar with that of the initial structure.

• Journal of Korean Association for Spatial Structures
• /
• v.11 no.2
• /
• pp.139-149
• /
• 2011

A cable structures have the advantage that cover a large space without column but it is very sensitive to deal with shape control because of its flexibility. Especially, location of control member and needed elongation of member are important things. Therefore, the purpose of this paper is studied on displacement control technique for pre-stressed cable structures by force method considering order of control. The layout of this paper is as follows. Firstly, in section 2, the control technique by force method for cable structures is given. Secondly, section 3 briefly introduces simple cable net in order to apply control technique considering ordering of actuator. Finally, more complex example for effective member and the conclusion are in section 4 and 5, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.1
• /
• pp.35-44
• /
• 2022

It is essential to control the lateral displacement and differential axial shortening of the vertical elements in high-rise buildings. Recently, an outrigger or a mega structure system has been adopted to control the lateral displacement. Furthermore, to resolve the problems caused by differential axial shortening in high-rise buildings, analytical prediction and correction is often studied; however, the study on the comparisons of the lateral load resisting systems to address differential axial shortening is less. Therefore, in this paper, a 60-story RC residential building using an outrigger or a mega structure system is analyzed with a construction sequence. Moreover, differential axial shortening can result in an additional member force of structural members and failure of non-structural members. These problems caused by differential axial shortening affects the behaviors and can damage the important structure member in the high-rise buildings. Hence, the effects of the systems on differential axial shortening between the vertical elements in high-rise buildings are studied.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.2
• /
• pp.237-247
• /
• 2011

This paper presents an improved initial force method for determining the initial shape of suspension bridges. After determining the initial shape factors through the force equilibrium conditions of each hanging point, the initial force method was applied with the computed values, each node's coordinates, and unstrained lengths of the cable element as inputs. The unstrained length of each cable element was regarded as a fixed value in each iteration step, unlike in the typical initial force method. This method can be applied to 2D and 3D suspension bridge models. The validity of the present method was demonstrated by comparing the results of the numerical examples.

• Journal of the Korean Society for Railway
• /
• v.6 no.4
• /
• pp.30-36
• /
• 2003

궤도(track)는 열차가 안전하고 승차감(乘車感)이 좋게 운행되도록 충분한 강도를 가지고 더욱이 양호한 상태로 정비되어 있어야 한다. 일반적으로, 토목구조물(structure)은 하중을 받으면 변위(變位)ㆍ변형하고, 하중이 없게 되면 원래대로 되돌아간다. 즉, 각 부재는 탄성 한계 내로 응력(應力)이 들어가도록 설계된다. 그러나, 궤도는 열차의 하중과 진동을 궤도 자신의 변위 축적으로 흡수하고 있다. 결국, 처음부터 틀림이 진행되어 가는 것을 전제로 한 유일한 구조물이다. 일반적으로는 스프링 하 중량과 축중(軸重)이 큰 차량이 빠르고 대량으로 주행하게 되면 궤도 틀림이 발생하여 진행한다. 궤도 틀림 파형의 성장은 궤도 틀림이라고 하는 공간적인 파형의 시간적인 추이라고 하는 2차원적인 취급이 필요하다. (중략)

• Magazine of the Korea Concrete Institute
• /
• v.4 no.2
• /
• pp.111-118
• /
• 1992

본 연구는 실리카흄을 혼화재료로 사용하여 1200kg/$ extrm{cm}^2$정도의 초고강도 콘크리트를 제조하였으며 이에 대한 재료특성을 실험 및 보부재의 휨거동을 실험을 실시 비교 분석하였다. 재료특성 실험으로는 기본적인 강도 시험, 파괴음 측정에 의한 AE실험 그리고 수은압입법에 의한 세공실험을 실시하였다. 초고강도 콘크리트의 재료특성치는 ACI 363의 고강도 콘크리트 재료특성 결가보다 크게 나타났으며 압축강도와 미세공극량은 선형적으로 비례하였다. 보부재의 휨특성을 파악하기 위해 인장철근비 변화, 전단보강근의 유무 및 철근 표면형상의 변화 등을 실험인자로 하였으며 각각의 현상을 비교분석함으로써 균열성상에 따른 하중-변위 관계, 중립축 이동에 따른 부재거동 및 응력블록의 변화에 관하여 비교 고찰하였다. 초고강도 콘크리트 사용한 보부재의 경우 중립축 상승으로 단면의 압축영역은 매우 작아져 급격히 압축파괴되는 경향을 보였으며 응력블록 형태는 삼각형의 분포를 보였다.

• Journal of the Korean Geosynthetics Society
• /
• v.9 no.2
• /
• pp.33-40
• /
• 2010

In this study, the pullout tests are conducted to evaluate pullout resistance of steel strip reinforcement with transverse members. The test results are compared with theoretical equations and then the failure mechanism of transverse members is evaluated. The bearing resistance stress(${\sigma}^{\prime}_b$) of transverse members, which is applied pullout force at 50mm displacement, is closed from punching shear failure to general shear failure. The behavior by increment of a number of transverse members became closer to general shear failure. The behavior of transverse members at maximum pullout force, which is closed to general shear failure, is indicated that it is unrelated to normal stress and a number of transverse members. However, if the allowable displacement of reinforced soil wall is considered, it is impossible to apply in design. The test results are compared with bearing resistance evaluations using Prandtl's plastic theory and cylindrical cavity expansion theory. The analysis results are indicated that the bearing resistance by pullout tests is closed to predicted result by Prandtl's plastic theory, which are located between general shear failure and punching shear failure.

• Journal of Korean Association for Spatial Structures
• /
• v.7 no.3 s.25
• /
• pp.79-86
• /
• 2007

Recently, as steel structures become higher and more long-spanned, construction of high-strength steels is increasing gradually. Application of high-strength steel can be possible to make a more light and economic steel structures by reducing thickness and space. To apply a high-strength steel to structure, criteria of high-strength steel for buckling is required. However, current specification is not sufficient for criteria of high-strength steels. In this paper, buckling behavior of high-strength steel truss columns with box sections is investigated by using three-dimensional elastic-plastic finite deformation analysis program. The criteria equation for allowable compressive stress of high-strength steel truss columns with box sections is proposed and confirmed the applicability. It is reasonable form analytical results that formulated equations after finding the upper limit of allowable axial direction compression stresses of high-strength steel truss columns. And new equation is suitable to buckling design of high-strength steel truss columns.