• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.293-303
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• 2010

The purpose of this study was to evaluate the influence of the methods of application of the direct analysis method, using the load amplification factor suggested by the KBC 2009 design code, for the evaluation of frame stability. For this purpose, the direct analysis method was performed for three-story-one-bay and five-story-three-bay unbraced steel frames with various notional loads, bending stiffness reductions, and factor B2s. The results of the analyses were compared with the results of the second-order inelastic analysis to evaluate the influence of the applied methods. The scale of the frame, the axial load ratio, and the axial load distribution pattern were added to the main parameters to investigate the external effects. The research results showed that the influence of the methods of application of the direct analysis method is not significant in the case of the required axial strength and the application of the additional notional loads; and that the application of the factor B2 with the story stiffness concept to the direct analysis method is appropriate for the required flexural strength.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.116-124
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• 2021

In this study, the reliability of vehicle frames employed in small electric road sweepers was assessed through durability testing. The frames were tested under three conditions, whereby mechanical loads were applied to (1) the entire frame, (2) the front frame, and (3) the rear frame. The strain distributions in the loaded frames were determined through a combination of direct strain gauge measurements and supplementary numerical analysis. While subtle differences were observed between the experimental and numerical analyses, both methods successfully yielded comparable deformation patterns. Thus, the dependence of stress distribution and the state of the frame on loading conditions could be fully identified through our combined structural and numerical analysis.

• Structural Engineering and Mechanics
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• v.25 no.2
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• pp.147-160
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• 2007

In this paper, a dynamic analysis based on the fuzzy set theory is presented as a possible complementary tool to the classical stochastic methods for dynamic analyses. Material parameters of a structure are influenced by uncertainties and therefore they are considered to be fuzzy quantities with given distributions, that means fuzzy numbers with given membership functions. The fuzzy dynamic analysis is conducted with help of fuzzy arithmetic defined on the so-called ${\alpha}$-cuts. The results of the analysis are also obtained in the form of fuzzy numbers, which compared to the stochastic methods is less computationaly expensive while at the same time they still provide information about the distribution of a quantity. This method is demonstrated on an analysis of a two-dimensional frame subjected to possible seismic load, where the uncertain eigenmodes and eigenfrequencies are used in the modal analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4611-4617
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• 2014

This paper proposes an approximate method to estimate member forces of columns in a rigid frame. One of the conventional methods, Cantilever Method assumes the midpoint of a column as a hinge and linear distribution of axial stresses regarding the centroid of the column areas. As a result, it shows erroneous results compared to those of matrix analysis of two frames. In this study, a new method is proposed to estimate the member forces in columns and location of hinges in columns, which can be adopted easily by a practicing engineer, and numerical examples showed improved results compared to conventional methods.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.2
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• pp.53-67
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• 2008

In this study, seismic control performance of friction dampers installed in a reinforced concrete shear wall-moment frame system, of which main lateral force resisting system is a shear wall, is investigated. Three configurations of friction dampers are investigated. One is a diagonal brace type reinforcing the shear wall directly, another is a diagonal brace type reinforcing the moment frame without the shear wall, and the other one is a vertical boundary element type installed at both ends of the shear wall. In addition, various levels of the total friction force and its distribution methods are examined. Time history analysis considering material nonlinearity is conducted for seismic loads increased by the enhanced design code compared to the initial design loads, and energy dissipation, lateral loads and structural member damages are analyzed. As a result, the shear wall-reinforcing diagonal brace type with the total friction force of 30 % of the reference friction force gives the best performance on the whole, and the distribution methods of the friction force do not have remarkable difference in effects. Also, concentrated installation in adjacent four stories shows just a little compromised control performance compared to the entire story installation.

• Magazine of the Korea Concrete Institute
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• v.3 no.3
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• pp.111-119
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• 1991

Most of the conventional aseismic design methods for reinforced concrete structures, based on the strong¬column weak-beam design concept, do not necessarily the state of damage distribution over the entire frame. This paper introduces a seismic damage-controlled design method for RC frames which aim at individual member damage indices. Three design parameters, namely the longitudinal steel ratio, the confinement steel ratio and the frame member depth, were studied for their influence on the frame response to an earthquake. The usefulness of this design method will be demonstrated with a three-bay four-story building frame so that, on the one hand, the method will reduce the damage as measured by the global damage index under the same earthquake and, on the other hand, will lead to a larger capacity enabling stronger earthquakes to be accom¬odated .

• Steel and Composite Structures
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• v.14 no.6
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• pp.523-545
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• 2013

In this study, the effect of presence and distribution of masonry infill walls on the mid-rise steel frame structures having soft ground storey was evaluated by implementing finite element (FE) methods. Masonry infill walls were distributed randomly in the upper storey keeping the ground storey open without any infill walls, thus generating the worst case scenario for seismic events. It was observed from the analysis that there was an increase in the seismic design forces, moments and base shear in presence of randomly distributed masonry infill walls which underlines that these design values need to be amplified when designing a mid-rise soft ground storey steel frame with randomly distributed masonry infill. In addition, it was found that the overstrength related force modification factor increased and the ductility related force modification factor decreased with the increase in the amount of masonry infilled bays and panels. These must be accounted for in the design of mid-rise steel frames. Based on the FE analysis results on two mid-rise steel frames, design equations were proposed for determining the over strength and the ductility related force modification factors. However, it was recommended that these equations to be generalized for other steel frame structure systems based on an extensive analysis.

• Structural Engineering and Mechanics
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• v.85 no.1
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• pp.55-64
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• 2023

Energy-based seismic design and evaluation methods are promising to be involved in the next generation design codes. Accordingly, determining the distribution of earthquake input energy demand among floor levels is quite imperative in order to develop an energy-based seismic design procedure. In this paper, peak floor input energy demands are achieved from relative input energy response histories of several reinforced concrete (RC) frames. A set of 22 horizontal acceleration histories selected from recorded near-fault earthquakes and scaled in time domain to be compatible with the elastic acceleration design spectra of Turkish Seismic Design Code are used in time history analyses. The distribution of the computed input energy per mass values and the arithmetic means through the height of the considered RC frames are presented as a result. It is found that spatial distribution of input energy per mass is highly affected by the number of stories. Very practical yet consistent formulation of distributing the total input energy to story levels is achieved, as a most important contribution of the study.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.205-213
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• 2008

Servicizing is defined 'not as to sell the products but as to sell the functions'. This study was done on the methods for revitalization as the object items of navigation & antenna among car parts. The direct door-to-door survey was done for 101 enterprises (direct-management stores) and percentage & t-test were done for statistics. The results can be summarized like followings. First, PR on servicizing is required. Second the optimized methods can be obtained by incorporating reuse & recycling distribution systems of servicizing with the existing recovery system Reuse distribution system can be constructed rationally because inventory control is being done correct1y with the periodic recovery. Finally, as for the analysis on the relative importance of main factors of servicizing, it shows that supports & providing the concrete frame of the government & local autonomous body are important.

• Journal of Contemporary Eastern Asia
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• v.16 no.2
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• pp.59-81
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• 2017

The emergence of the new audiences floating across multimedia platforms and engaging in TV production and distribution have forced producers and broadcasters to think of not only the fragmented distribution of their content but also the development of a new format beyond the frame of traditional TV production. A Korean entertainment TV show My Little Television combining the form of live webcasting and traditional TV show reflects such a trend. Because of the distinct format, My Little Television carries out a unique strategy in managing the two screens - Internet and TV. The dualistic production requires all players to understand not only online subculture and communication styles and methods, but also implicit and explicit rules of traditional TV production. Through text and visual image analysis on the show, this study discusses how MLT negotiates with the original Internet text, the producers' paratext, and the supertext of the national TV network in the context of the transitory screen culture.