• Journal of the Korea Concrete Institute
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• v.12 no.6
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• pp.119-126
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• 2000

Reinforced concrete structural walls are widely known to provide an efficient lateral load resistance and drift control. However, many reported researches on them are mostly limited to the RC structural walls reinforced according to seismic details. When the pushover analysis technique is used for the prediction of inelastic behavior of frame-wall structures for the seismic evaluation of existing buildings having non-seismic details, the reliability of this analysis method should be checked by the test results. The objective of this study is to verify the correlation between the experimental and analytical responses of a high-rise reinforced concrete frame-wall structure having non-seismic details by using DRAIN-2DX program[11] and the test results performed previously[1]. It is concluded that the behavior of the frame-wall model is mainly affected by the fixed-end rotation(uplift at base) and bending deformation of the wall and that the analysis with the LINKS model[10] in DRAIN-2DX describes them with good reliability.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.66-71
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• 2013

There is a critically structural problem of scaffolding system when one of scaffold columns is remove to be used as a gangway for their temporary office in the structure before finishing all such as an apartment or office building. This is not used to checking to structurally checking at a construction site. This study is to find out which system at a site will be more effective and low-cost-high effectiveness of aluminum ladder, timber ladder, ${\phi}$1/2 inch steel pipe truss with a type of concave, convex warren truss ladders. Theses are structurally tested with horizontal set as a truss type with 1.8 meter long. Concentrated load has been loaded at the upper center of the system and checked its strain at the bottom center, using aluminum-use strain gage and steel-use gauge have been attached concave warren truss with diameter 1/2 inch has 14% stronger than convex truss. Convex truss has almost same strength as an aluminum ladder truss, it is found out.

• Journal of Korean Society of Steel Construction
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• v.15 no.3
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• pp.281-290
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• 2003

A series of connection tests of portal frames which were composed of cold-formed steel studs and rafters was carried out to study the moment-rotation relation, the rotational rigidity, and the yield and the ultimate moment of the connections. The main factors of the tests were the thickness, the shape of the connecting members which were made of mild steel, and the torsional restraints of the test specimens. The test results were compared with those obtained through the non-linear analysis, for verification. The secant stiffness estimated from the experimental moment-rotation curve was proposed for the rotational rigidity of semi-rigid connections, and its validity was verified in the structural frame analysis.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.611-623
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• 1997

This paper provides the results of an experimental and analytical study performed on the beam to Concrete Filled Circular Steel Column connections with the external stiffener rings under the gravity loads. Specimens are modeled as a 1/4 scale of the beam-columns as gravity loads are applied to a multi-story frame. Important parameters in this study are the width of the external rings, the diameter-thickness ratios of column and whether or not the external rings are welded to the circular column. A total of 20 specimens are tested to clarify the structural behavior of the CFT column connections with the external stiffener rings. The test results are summarized for the yield and maximum strength and stiffness. The existing design equations for the allowable and yield load capacities are referred to verify the structural characteristics for the connections.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.21-24
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• 2011

Oil Tight Bulkhead (O. T. Bulkhead) is one of the most important structural members of oil tankers in the views of vessel's strength and safety. Therefore O.T. bulkhead's strength should be sufficient against relevant loadings, which is normally verified by local scantling requirement and structural strength analysis defined in CSR (Common Structure Rules for Double Hull Oil Tankers). However, there is a weak-able situation when the vertical stiffeners are cut due to the penetration of cargo pipes through O. T. Bulkhead. In addition, CSR does not define how to prove the strength of this case. Therefore it is necessary to verify the structural adequacy in case that several vertical stiffeners are discontinued. This article intends to prove the strength of O. T. Bulkhead with five (5) vertical stiffeners discontinued due to pipes' penetration using the grillage analysis and the finite element analysis and to provide proper reinforcement.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.5
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• pp.451-458
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• 2008

In this study 3- and 6-story flat plate structures designed only for gravity load are retrofitted with steel plates and braces and their seismic performances are evaluated to verify the effect of seismic retrofit. According to the analysis results obtained from nonlinear static and dynamic analyses both the strength and stiffness are significantly enhanced as a result of the seismic retrofit. Especially the effect of column jacketing could be enhanced significantly when slabs were reinforced to prevent premature punching shear failure. When buckling-restrained braces are used instead of conventional braces, the structures showed more ductile behavior, especially in the 3-story structure.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.1
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• pp.1-8
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• 2019

In this study, the effectiveness of a multi-action hybrid damper (MHD) composed of lead rubber bearing (LRB) and friction pad was verified in terms of seismic performance improvement of a frame structure. The LRB and the friction elements are connected in series, so the LRB governs the intial small deformation and the friction determines large deformation behavior. Cyclic loading tests were conducted by using a half scale steel frame structure with the MHD, and the results indicated that the structure became to have the stable trilinear hysteresis with large initial stiffness and first yielding due to the LRB, and the second yielding due to the friction. The MHD could significantly increase the energy dissipation capacity of the structure and the hysteresis curves obtained by tests were almost identical to the analytically estimated ones.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.181-188
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• 2007

This research presents two methods to prevent local buckling from circular tube brace and then verify their performance capacity through a cyclic loading test. As control methods on local buckling, one is to restrict local buckling as attaching cover plate at range of buckling. And the another is to exclude danger of buckling as inserting contraction device with rod and spring at the center of brace. The purpose of this research is to develop structural device for restriction of local buckling or for exclusion of its. And we investigate appliance of suggested methods through an experiment. We also estimate the improvement of performance capacity in a quantitative respect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.440-447
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• 2020

Masonry structures are used as bearing walls in small buildings, but they are generally considered non-bearing walls. They are used as partition walls that divide the interior spaces of the frame structures of buildings. In addition, wetting techniques that use mortar as an adhesive between blocks or bricks in construction are vulnerable to climatic conditions, especially cracks in mortar, which can cause conduction collapse of the walls in seismic loading. The purpose of this research was to propose a dry concrete block construction method that complements the weak axial shear stiffness and improves the weakness of the wet construction method as well as to investigate its structural behavior. In this study, the material properties of concrete blocks were examined, and the seismic performance of the proposed dry assembly structure was verified by structural behavior tests on horizontal cyclic loads. First, in these study results, concrete blocks can be applied to the dry block construction method instead of wet construction methods because they secure more than C-type blocks in KS regulations. Second, the structural performance of the wall against a horizontal cyclic load indicates that the resisting force of the assembly block wall is increased by increasing the horizontal length of the wall, forming several diagonal cracks. Finally, the proposed dry block wall structure requires a seismic performance assessment considering that the ratio of the shape of the wall by height and length is considered a major influence variable on the structural behavior under a horizontal load.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.255-263
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• 2017

This paper presents a beam element capable of conducting material and geometric nonlinear analysis for applications requiring the ultimate behavioral analysis of structures with composite cross-sections. The element formulation is based on co-rotational kinematics to simulate geometrically nonlinear behaviors, and it uses the fiber section method to calculate the stiffness and internal forces of the element. The proposed element was implemented using an in-house numerical program in which an arc-length method was adopted to trace severe nonlinear responses(such as snap-through or snapback), as well as ductile behavior after the peak load. To verify the proposed method of element formulation and the accuracy of the program that was used to employ the element, several numerical studies were conducted and the results from these numerical models were compared with those of three-dimensional continuum models and previous studies, to demonstrate the accuracy and computational efficiency of the element. Additionally, by evaluating an example case of a frame structure with a composite member, the effects of differences between composite material properties such as the elastic modulus ratio and strength ratio were analyzed. It was found that increasing the elastic modulus of the external layer of a composite cross-section caused quasi-brittle behavior, while similar responses of the composite structure to those of homogeneous and linear materials were shown to increase the yield strength of the external layer.