• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.15 no.2
• /
• pp.293-303
• /
• 2002

Recently, the use of the high strength materials and development of construction techniques have resulted in more flexible and longer spanning in the stadium systems. So the natural frequency of stadium structures are became low. Stadium stand could be led to significant dynamic response as like resonance due to spectator rhythmical activities. The accurate analysis of dynamic behavior of stadium systems and the precise investigation of the dynamic loads on stadium structures are demanded for effective design. It is desirable to apply measured dynamic loads created by spectator activities because these dynamic loads are not easy to express numerical formula. As the floor mesh of stadium stand is refined, the number of divided elements increases in numerical analysis. the rise of the number of elements makes the numbers of nodal points increased and numerous computer memory required. So it is difficult to analysis refine full model of stadium structures by using the commercial programs. In this study, the various dynamic loads induced by spectator movements are measured and analyzed. And a new modeling method that reduce the nodal points are introduced. Vibration analysis of stadium stands is executed to inspect accuracy and efficiency of proposed method in this paper.

• Journal of Korean Society of Steel Construction
• /
• v.10 no.3 s.36
• /
• pp.487-495
• /
• 1998

Recently, the space truss has been attracted by many designers because of their ability to support significant loads with a minimum material. And it is relatively flexible to design the configuration of structures. This paper presents a volume optimization for the space truss on the basis of result evaluated from nonlinear analysis. The optimization of the truss is done by nonlinear optimum GINO(General Interactive Nonlinear Optimizer) program. The objective function considered is the volume of the steel bars. The constraints for optimum design are the design limits, such as the axial force strength, maximum slenderness, minimum thickness, allowable deflection and ratio of the external diameter to thickness of the circular tube bars.

• Journal of Korean Society of Steel Construction
• /
• v.20 no.5
• /
• pp.665-673
• /
• 2008

The composite structures of steel and reinforced concrete, which have been widely used in large-scale concrete structures, werestudied to investigate the cause of unexpected cracks and to verify the composite actions between the two materials. Vertical stiffeners between flanges, studs and dowel bars, stirrups, and concrete strength were chosen as experimental variables in afour-point loading test. The results showed that the vertical stiffener prevented not only the local web buckling, but also bond failures between steel and concrete. It increased the flexural resistance (fracture loads) due to the composite action of two materials, compared withthose of any experimental variable. However, the composite behavior of steel reinforced concrete beam was not affected seriously by additional studs, dowel bars, stirrups, and concrete strength.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.2
• /
• pp.109-116
• /
• 2003

An investigation on the structural behavior of cold-formed steel lipped C-section stud for interior walls or partitions was carried out. This experimental research was carried out to study the ultimate and service load capacity of stud assemblies that are subjected to lateral loads. Each test specimen consisted of three or four lipped C-section studs and two C-section tracks that restrained both ends. The major factors considered in this experiment were the perforation on the web, the connection of the bridge channel and the special clip. The effect of the plaster board and the ply wood, which were attached to the tension flange on the flexural strength, was also investigated. Thereafter, the test strength capacities were compared with the nominal strength, based on the AISI Specifications (1996).

• Journal of Korean Society of Steel Construction
• /
• v.15 no.2
• /
• pp.207-217
• /
• 2003

The Concrete Filled Steel Tube (M) Column has excellent structural capacities that are in accordance with the interaction effect between the steel tube and concrete. CFT structure has been focussed on a struc tural system for high-rise buildings. The purpose of this study is to evaluate the strength and deformation capacities of CFT columns that are subject to constant axial and cyclic lateral load. The test parameters are diameters to the thickness ratio of the steel tube, axial load ratios, and the shapes of the tube. Total eighteen specimens were fabricated to clarify the energy absorption capacity of the CFT columns. Experimental results were summarized for their ultimate strengths and deformation capacities.

• Journal of Korean Society of Steel Construction
• /
• v.21 no.2
• /
• pp.145-154
• /
• 2009

This study discusses the inelastic behavior of single-layer latticed dome, which consists of a tubular truss member and newly proposed joint sections, through a loading test on a scaled-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. The maximum applied load was nearly 1.6 times of the design load, and structural failure occurred after exceeding the compressive yielding in some members. Structural displacement was maintained up to the limit of the oil jack. The behavior of the latticed dome from the loading test was analyzed according to the order of loading steps.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.1
• /
• pp.71-80
• /
• 2006

The behaviors of steel-plate shear panels were investigated through an experimental and analytical study, using mild steel (S40). Steel-plate shear panels buckle at small loads, and their strength is based on the shear panel's postbuckling strength due to tension field action. In design practice, however, the capacity of steel-plate shear panels is limited to the elastic buckling strength of shear panels. Th e National Standard on Limit States Design of Steel Structures, CAN/CSA-S16.1-94 (1994) contains a guideline for the analysis of thi n, unstiffened, steel-plate shear walls using the strip model. In this paper, the structural capacity of shear panels was evaluated using the results of the experiment and of the strip model analysis.

• Wind and Structures
• /
• v.12 no.4
• /
• pp.313-332
• /
• 2009

This paper numerically and experimentally investigates the control performance of the active mass damper (AMD) systems in a 26-story high-rise building in use. This is the first full-scale application of the AMD system for suppressing the wind-induced vibration of a building structure in Korea. In addition, the AMD system was installed on top of the building already in use, which may be the world's first implementation case. In order to simultaneously mitigate the transverse-torsional coupled vibration of the building, two AMD systems were applied. Moreover, the H-infinity control algorithm has been developed to utilize the maximum capacity of the AMD system. From the results of numerical simulation using the wind load obtained from the wind tunnel tests, it was found that the maximum acceleration responses of the building were reduced significantly. Moreover, the control performance of the installed AMD system was examined by carrying out the free and forced vibration tests. The acceleration responses on top of the building in the controlled case measured under strong wind loads were compared with those in the uncontrolled case numerically simulated by using the wind load deduced from the measured data and a structural model of the building. It is demonstrated that the AMD system shows good control performance in reducing the building accelerations.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.4 no.2
• /
• pp.9-14
• /
• 2008

400RT geothermal system which is consist with vertical-typed 112 geothermal heat exchangers is measured and evaluated in spring, 21st${\sim}$24th May 2008. As the results, the average temperature difference between inlet and outlet of geothermal pipes is $1{\sim}2^{\circ}C$ and that of cool water supply is $2{\sim}6^{\circ}C$, when being normally operated. Despite temperature fluctuations by cooling loads, the average temperature difference between main pipes of inlet and outlet of geothermal heat exchangers is measured as $3^{\circ}C$. The geothermal system COPs are calcluated as 2.92${\sim}$3.92 in every 12 hours.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.11a
• /
• pp.263-264
• /
• 2012

In this study, the ultra high strength concrete which have 100, 150, 200MPa took the heat from 20℃ to 70 0℃ and the 0, 20% stress in normal condition's to evaluate stress-strain, residual compressive strength and thermal expansion deformation were evaluated. The heating speed of specimen was 0.77℃/min 20~50℃, 50℃ before the target temperature, and the other interval's heating speed was 1℃/min. As a result, the stress-strain curve of non-load specimen showed the liner behavior at high temperature when the specimen's strength increased more. If ultra high strength concrete got loads, its compressive strength tended to decrease different from the normal strength concrete. The thermal expansion deformation was expanded from a vitrification of quartz over 500℃. however, over the 600℃, it was shrinked because of the dehydration of the combined water.