• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.143-150
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• 1997

Generally, the problem of vertical vibration of structure is generated slab. Analysis of space framed structures with slab for vertical vibration requires more efficient modeling and analysis technique, because number of elements lead to more complicated model with many degree of freedom which requires large amount of computing resources for dynamic analysis. This paper propose an efficient analysis method for vertical vibration of space framed structure with slab. At first, proposed model is selected minimum joints and degree of freedom which are acquired sufficient dynamic response to the vertical vibration. Secondly, super-elements that are made a number of element are used for simple input data and fast analysis.

• 한국농공학회지
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• 제40권1호
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• pp.78-87
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• 1998

In this study, semi-rigid light-weight framed structures analysis model (SERIFS) was developed by advancing the LEIFS model. This model enables us to analyze simultaneous effects of large deflection and semi-rigid connection by computing unbalanced load occurring in the process of repeated loading through equalization of bending moments and torsion. This model is also able to handle the effect of the semi-rigid connection and large deflection by modifying the elastic stiffness matrix using moment-rotation behavior of connection. Moment-rotation behavior of the semi-rigid connection was adopted from the experimental results of load-vertical displacement of frame element In conclusion, this model achieves to analyze the nonlinear and large deflection behavior on the semi-rigid and light-weight steel frame connection.

• 콘크리트학회지
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• 제13권6호
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• pp.121-126
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• 2001

• Selected Papers of The Society of Naval Architects of Korea
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• 제1권1호
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• pp.26-36
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• 1993

In this paper, a thoery for the static analysis of large plastic deformations of 3-dimentional frames, aiming at application to the collapse analysis of ship structures, is presented. In the frame analysis formulation, effects of shear deformations are included. A plastic hinge is inserted into the field of a beam and post-failure deformation of the plastic hinge is characterized by finite rotations and extensions. In order to model deep web frames of ship's structures into a framed structures, collapse of thin-walled plate girders is investigated. The proposed analysis method is applied to several ship structural models in the references.

• Structural Engineering and Mechanics
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• 제61권4호
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• pp.497-510
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• 2017

A framed structure may be composed of two sub-structures, which are linked by a hinged joint. One sub-structure is the primary system and the other is the secondary system. The primary system, which is subjected to the periodic external load, can give rise to an auto-parametric resonance of the second system. Considering the geometric-stiffness effect produced by the axially internal force, the element equation of motion is derived by the extended Hamilton's principle. The element equations are then assembled into the global non-homogeneous Mathieu-Hill equations. The Newmark's method is introduced to solve the time-history responses of the non-homogeneous Mathieu-Hill equations. The energy-growth exponent/coefficient (EGE/EGC) and a finite-time Lyapunov exponent (FLE) are proposed for determining the auto-parametric instability boundaries of the structural system. The auto-parametric instabilities are numerically analyzed for the two frames. The influence of relative stiffness between the primary and secondary systems on the auto-parametric instability boundaries is investigated. A phenomenon of the "auto-parametric internal resonance" (the auto-parametric resonance of the second system induced by a normal resonance of the primary system) is predicted through the two numerical examples. The risk of auto-parametric internal resonance is emphasized. An auto-parametric resonance experiment of a ${\Gamma}$-shaped frame is conducted for verifying the theoretical predictions and present calculation method.

• 한국전산구조공학회논문집
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• 제13권3호
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• pp.351-360
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• 2000

복수의 내부튜브를 가진 골조 튜브 시스템의 전단지체 영향을 평가하기 위하여 수치적인 모델링 기법이 제안되었다. 이러한 튜브 구조물의 모든 튜브는 전단지체 영향 뿐만 아니라 휨과 전단변형의 영향을 설명할 수 있는 보로 각각 모델링된다. 수치적인 해석은 최소 포텐셜 에너지 원리에 근거한 변분 접근법에 기초한다. 복수의 내부튜브를 가진 튜브 구조물의 전단지체 현상이 부가적인 휨 응력에 의해서 조사되었다. 또한 튜브 구조물의 전단지체를 지배하는 구조변수를 연구하기 위하여 33개의 튜브구조물이 해석되었다.

• Earthquakes and Structures
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• 제8권2호
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• pp.379-399
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• 2015

Existing building structures can easily present material mechanical properties which can largely vary even within a single structure. The current European Technical Code, Eurocode 8, does not provide specific instructions to account for high variability in mechanical properties. As a consequence of the high strength variability, at the occurrence of seismic events, the structure may evidence unexpected phenomena, like torsional effects, with larger experienced deformations and, in turn, with reduced seismic performance. This work is focused on the torsional effects related to the irregular stiffness and strength distribution due to the concrete strength variability. The analysis has been performed on a case-study, i.e., a 3D RC framed 4 storey building. A Normal distribution, compatible to a large available database, has been taken to represent the concrete strength domain. Different plan layouts, representative of realistic stiffness distributions, have been considered, and a statistical analysis has been performed on the induced torsional effects. The obtained results have been compared to the standard analysis as provided by Eurocode 8 for existing buildings, showing that the Eurocode 8 provisions, despite not allowing explicitly for material strength variability, are conservative as regards the estimation of structural demand.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.3-10
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• 2001

The box system that is composed only of reinforced concrete walls and slabs are adopted on many high-rise apartment buildings recently constructed in Korea. And the framed structure with shear wall core that can effectively resist horizontal forces is frequently adopted for the structural system for high-rise building structures. In these structures, a shear wall may have one or more openings for functional reasons. It is necessary to use subdivided finite elements for accurate analysis of the shear wall with openings. But it would take tremendous amount of computational time and memory if the entire building structure is subdivided into a finer mesh . An efficient analysis method that can be used regardless of the number, size and location of openings is proposed in this study, The analysis method uses super element, substructure, matrix condensation technique and fictitious beam technique. Three-dimensional analyses of the box system and the framed structure with shear wall core having various types of openings were performed to verify the efficiency of the proposed method. It was confirmed that the proposed method have outstanding accuracy with drastically reduced time and computer memory from the analyses of example structures.

• Structural Engineering and Mechanics
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• 제27권2호
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• pp.135-148
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• 2007

A new finite shear wall element model and a method for calculation of 3D multi-storied only shear walled or shear walled - framed structures using finite shear wall elements assumed ideal elasto - plastic material are developed. The collapse load of the system subjected to factored constant gravity loads and proportionally increasing lateral loads is calculated with a method of load increments. The shape functions over the element are determined as a cubic variation along the story height and a linear variation in horizontal direction because of the rigid behavior of the floor slab. In case shear walls are chosen as only one element in every floor, correct solutions are obtained by using this developed element. Because of the rigid behavior of the floor slabs, the number of unknowns are reduced substantially. While in framed structures, classical plastic hinge hypothesis is used, in nodes of shear wall elements when vertical deformation parameter is exceeded ${\varepsilon}_e$, this node is accepted as a plastic node. While the system is calculated with matrix displacement method, for determination of collapse safety, plastic displacements and plastic deformations are taken as additional unknowns. Rows and columns are added to the system stiffness matrix for additional unknowns.

• Earthquakes and Structures
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• 제9권2호
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• pp.321-337
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• 2015

Existing building structures can easily present material mechanical properties which can largely vary even within a single structure. The current European Technical Code, Eurocode 8, does not provide specific instructions to account for high variability in mechanical properties. As a consequence of the high strength variability, at the occurrence of seismic events, the structure may evidence unexpected phenomena, like torsional effects, with larger experienced deformations and, in turn, with reduced seismic performance. This work is focused on the reduction in seismic performance due to the concrete strength variability. The analysis has been performed on a case-study, i.e., a 3D RC framed 4 storey building. A Normal distribution, compatible to a large available database, has been taken to represent the concrete strength domain. Different plan layouts, representative of realistic strength distributions, have been considered, and a statistical analysis has been performed on the induced reduction in seismic performance. The obtained results have been compared to the standard analysis as provided by Eurocode 8 for existing buildings. The comparison has shown that the Eurocode 8 provisions are not conservative for existing buildings having a large variability in concrete strength.