• 동력기계공학회지
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• 제19권2호
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• pp.78-83
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• 2015

In Korea, multi-housing in one of the most common types of residential space due to its easy management and convenience. In particular, south-facing plate-type(一) multi-housing has attracted a great deal of public interest because it consumes less energy compared with other types of multi-housing, making it advantageous from an energy-saving perspective. Although there have been many studies on the annual energy consumption of multi-housing in relation to building shape and area of window, there have not been sufficient research on the annual energy consumption of multi-housing in relation to individual units of the multi-housing. The purpose of this study is to propose a strategy for reducing energy consumption in plate-type(一) multi-housing, taking the units with the lowest energy consumption as the standard. The result, Standard Models's energy load was as 4000 ~ 5600kWh, and Passive Houses's energy load was less than Stand Models at the 1600kWh.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.5221-5229
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• 2013

본 연구의 목표는 한국형 피난 시뮬레이션 시스템을 개발하기 위한 한국형 피난부하모델을 구축하는 것이다. 이를 위해, 피난실험을 통해 도출된 한국인의 연령 및 장애유형별 피난속도와 선행연구에서 검증된 피난시간 계산 수식을 적용하였다. 그 결과, 건물 내부의 복도와 계단 및 출입구 정보를 바탕으로 각각의 유형(연령, 장애정도 등)에 따른 재실자의 피난시간을 도출할 수 있는 피난부하모델을 도출하였다. 피난부하모델의 검증을 위하여, 기존의 피난속도 계산 프로그램인 SIMULEX와 동일한 조건하에서 피난시간을 도출하여 비교평가하였다. 피난속도가 느릴수록 상호간의 계산결과가 비슷하였지만, 피난속도가 빨라지면 도출된 피난시간 결과값이 상이함을 알 수 있었다. 이는 한국형 피난부하모델과 SIMULEX의 피난속도 계산식 함수가 상이한 것에 기인한다.

• 한국항공우주학회지
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• 제39권7호
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• pp.643-651
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• 2011

본 논문에서는 전단하중을 받는 다양한 알루미늄 샌드위치 체결부의 파손 특성에 대한 시험 연구를 수행하였다. 3종류의 인서트 형식 체결부와 2종류의 포팅 형식 체결부에 대해 총 60개의 시편을 제작하여 시험을 수행하였다. 시험 결과, 인서트 형식 체결부의 경우 쓰루 클리어런스(through-clearance) 인서트를 사용한 경우의 파손하중이 가장 높게 나타났으며 포팅 형식 체결부의 경우 딤플 와셔(dimple washer)가 있을 때 전단하중이 약10% 향상되는 것을 확인할 수 있었다. 예상대로 면재의 두께가 증가할수록 전단파손하중도 증가하고, 특히 하중치구와 접촉하고 있는 상부 면재의 효과가 지배적인 것을 확인하였다.

• 한국도로학회논문집
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• 제8권3호
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• pp.21-28
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• 2006

Field or laboratory wheel tracking tests have been employed for the evaluation of the rutting potential of asphalt paving mixtures. Compared to field tests, laboratory wheel tracking tests are much less expensive and more manageable for most road projects. However, most test laboratories are not equipped to perform such tests because there does not exist any standard test procedure, and the required equipment is rather expensive. Futhermore, the size of test specimens and the relatively large quantity of test mixture required present difficulties for laboratory specimen mixing and compaction. This paper describes a project conducted to study the feasibility of replacing wheel tracking testsby a repeated-load creep test for rutting potential evaluation. Comparisons were made between the results of the two tests for different test temperatures, loading speeds and applied pressures. Three types of asphalt mixtures were studied in the test program. Favorable conclusions concerning the use of the repeated-load test for rutting potential evaluation were drawn based on the findings of the experimental test results. The correlation between the two types of tests was found to be good for all threeasphalt mixtures. Adopting the repeated-load creep test would lead to cost savings since it employs standard test equipment already available in most laboratories. It would also result in substantial time savings due to the much smaller quantity of mix needed, and the ease in specimen preparation.

• 조명전기설비학회논문지
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• 제20권10호
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• pp.172-177
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• 2006

본 연구에서는 배전계통의 부하지점의 부하형태에 따른 정전비용의 영향을 고려하여 분산전원을 설치함으로써 운영비용 및 정전비용을 최소화하는 방안을 제안하였다. 가정용, 산업용, 상업용, 사무용 및 농업용 등 부하형태를 실제 계통과 유사하게 고려함으로써 정확한 신뢰도 지수와 운영비용을 구할 수 있고, 이를 통해 총 운영비용 최소화에 더욱 접근할 수 있다. 특히 정전시 각 부하지점에 설치된 분산전원에 의해 전력이 공급되어 전력구입 비용과 정전비용의 경우 효과적으로 감소됨을 알 수 있었으며, 정전빈도와 정전시간이 감소되어 전력 공급률이 향상되어 신뢰도 지수가 좋아졌음을 알 수 있었다.

• Steel and Composite Structures
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• 제5권6호
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• pp.459-484
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• 2005

In recent years, the use of steel tube confined concrete (STCC) columns has been the interests of many structural engineers. The present study is an attempt to study the monotonic and cyclic behaviours of STCC columns. For the monotonic behaviours, a series of tests on STCC stub columns (twenty one), and beam-columns (twenty) were carried out. The main parameters varied in the tests are: (1) column section types, circular and square; (2) tube diameter (or width) to thickness ratio, from 40 to 162, and (3) load eccentricity ratio (e/r), from 0 to 0.5. For the cyclic behaviours, the test parameters included the sectional types and the axial load level (n). Twelve STCC column specimens, including 6 specimens with circular sections and 6 specimens with square sections were tested under constant axial load and cyclically increasing flexural loading. Comparisons are made with predicted column strengths and flexural stiffness using the existing codes. It was found that STCC columns exhibit very high levels of energy dissipation and ductility, particularly when subjected to high axial loads. Generally, the energy dissipation ability of the columns with circular sections was much higher than those of the specimens with square sections. Comparisons are made with predicted column strengths and flexural stiffness using the existing codes such as AIJ-1997, AISCLRFD- 1994, BS5400-1979 and EC4-1994.

• Steel and Composite Structures
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• 제19권6호
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• pp.1333-1354
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• 2015

A higher order analytical solution for static analysis of a truncated conical composite sandwich panel subjected to different loading conditions was presented in this paper which was based on a new improved higher order sandwich panel theory. Bending analysis of sandwich structures with flexible cores subjected to concentrated load, uniform distributed load on a patch, harmonic and uniform distributed loads on the top and/or bottom face sheet of the sandwich structure was also investigated. For the first time, bending analysis of truncated conical composite sandwich panels with flexible cores was performed. The governing equations were derived by principle of minimum potential energy. The first order shear deformation theory was used for the composite face sheets and for the core while assuming a polynomial description of the displacement fields. Also, the in-plane hoop stresses of the core were considered. In order to assure accuracy of the present formulations, convergence of the results was examined. Effects of types of boundary conditions, types of applied loads, conical angles and fiber angles on bending analysis of truncated conical composite sandwich panels were studied. As, there is no research on higher order bending analysis of conical sandwich panels with flexible cores, the results were validated by ABAQUS FE code. The present approach can be linked with the standard optimization programs and it can be used in the iteration process of the structural optimization. The proposed approach facilitates investigation of the effect of physical and geometrical parameters on the bending response of sandwich composite structures.

• 한국농공학회지
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• 제36권3호
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• pp.84-89
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• 1994

Section forces of greenhouse structures were studied to suggest basic information for the structural design of greenhouses with respect to roof types and support conditions. Structural analyses were performed for pitched and arched roof, and fixed and hinged support under snow loads and wind loads. Followings are the results obtained and are expected to be useful in determining the span length and roof type in greenhouse design. 1. Special considerations might he required for roof design at the heavy snow region, and for the support design at the strong wind region, respectively. 2. Single-span structure was found to be stronger than multi-span structure under the snow load, but the former was found to be weaker than the latter under the wind load. 3. Arched roof structure was expected to be safer than pitched roof structure if the dimensions and loads were equal. 4. Greenhouse orientation and roof slope should be considered in optimum structural design of grrenhouses, because these two factors are closely related with the influence of wind load and snow load.

• Structural Engineering and Mechanics
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• 제67권2호
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• pp.115-123
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• 2018

By using the first order shear deformation plate theory (FSDT) in the present paper, the effect of porosity on the buckling behavior of carbon nanotube-reinforced composite porous plates has been investigated analytically. Two types of distributions of uniaxially aligned reinforcement material are utilized which uniformly (UD-CNT) and functionally graded (FG-CNT) of plates. The analytical equations of the model are derived and the exact solutions for critical buckling load of such type's plates are obtained. The convergence of the method is demonstrated and the present solutions are numerically validated by comparison with some available solutions in the literature. The central thesis studied and discussed in this paper is the Influence of Various parameters on the buckling of carbon nanotube-reinforced porous plate such as aspect ratios, volume fraction, types of reinforcement, the degree of porosity and plate thickness. On the question of porosity, this study found that there is a great influence of their variation on the critical buckling load. It is revealed that the critical buckling load decreases as increasing coefficients of porosity.

• 한국지진공학회논문집
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• 제27권4호
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• pp.171-180
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• 2023

This study proposed a seismic reinforcement of RC columns with non-seismic details, a fiber reinforcement method of aramid sheets and MLCP (high elasticity aromatic polyester fiber material) with different characteristics, and 4 full-size column specimens and conducted experiments. The results show that a non-seismic specimen (RC-Orig) rapidly lost its load-bearing capacity after reaching the maximum load, and shear failure occurred. The RC column reinforced with three types of aramid did not show an apparent increase in strength compared to the unreinforced specimen but showed a ductile behavior supporting the load while receiving a lateral displacement at least 1.57 to 1.95 times higher than the unreinforced specimen. The fracture mode of the specimen, according to the application of lateral load, also changed from shear to ductile fracture through aramid-based reinforcement. In addition, when examining the energy dissipation ability of the reinforced specimens, a ductile behavior dissipating seismic energy performed 4 times greater and more stably than the existing specimens.