• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.275-282
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• 2011

A recent development of seismic design, which is required among environmentally friendly members, increased the concern on light-weight concrete. Extending around the building, the structural design which is applied for light-weight concrete has been increased. This study therefore evaluates the bending resistance and the shear resistance involved using four specimens that were manufactured and tested. The parameters used in this study exist. This study investigates the structural performance of composite slab using light-weight concrete with KCI (2007).

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.5-13
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• 2004

Strength and compressibility characteristics of Light-Weighted Foam Soil (LWFS) are experimentally investigated in the paper. LWFS is composed of the dredged soils, cement and air foam to reduce unit-weight and to increase compressive strength. For these purposes, both unconfined compression tests and triaxial compression tests are carried out fer artficially prepared specimens of LWFS with various initial water contents, cement contents, mixing ratio of silty dredged soils and different confining stresses. The experimental results of LWFS indicate that the stress-strain relationship and the compressive strength are strongly influenced by cement contents rather than intial water contents of the edged soils. In this paper, the normalizing scheme considering the ratio of initial water contents, cement contents, and air foam contents has been proposed to evaluate the relationship between compressive strength of LWFS and a normalized factor.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.221-228
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• 2004

Basic properties of artificial lightweight aggregate by using waste dusts and strength properties of LWA concrete were studied. Bulk specific gravity and water absorption of artificial lightweight aggregates varied from 1.4 to 1.7 and 13 to 16%, respectively. Crushing ratio of artificial lightweight aggregate was above 10% higher than that of crushed stone or gravel. As a result of TCLP leaching test, the leaching amount of tested heavy metal element was below the leaching standard of hazardous material. Slump, compressive strength and stress-strain properties of LWA concrete made of artificial lightweight aggregate were tested. Concrete samples derived from LWA substitution ratio of 30 vol% and W/C ratio of 45 wt% showed the best properties overall. Thermal insulation and sound insulation characteristics of light weight concrete panel with the optimum concrete proportion were tested. Average overall heat transmission of 3.293W/㎡$^{\circ}C$ was observed. It was higher by about 15% than those of normal concrete made by crushed stone. Sound transmission loss of 50.9 ㏈ in frequency of 500 ㎐ was observed. It was higher by about 13% than standard transmission loss.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.9-20
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• 2019

The number of natural disasters in Korea, such as earthquakes, is increasing. As a result, there is growing need for temporary residences or shelters for disaster conditions. The aim of this study was to produce post-disaster refugees housing differentiated from existing shelters using lightweight composite panels. To accomplish this, the structural performance of lightweight composite panels was validated, and an in-plane shear strength test was conducted according to the ASTM E72 criteria among the performance test methods for panels. As a result of the experiment, the maximum load for each specimen under an in-plane shear load was determined. All the experiments ended with the tear of the panel's skin section. The initial stiffness of the specimens was consistent with that predicted by the calculations. On the other hand, local crushing and tearing, as well as the characteristics of the panel, resulted in a decrease in stiffness and final failure. Specimens with an opening showed a difference in stiffness and strength from the basic experiment. The maximum load and the effective area were found to be proportional. Through this process, the allowable shear stress of the specimens was calculated and the average allowable shear stress was determined. The average ultimate shear stress of the lightweight composite panels was found to be $0.047N/mm^2$, which provides a criterion of judgement that could be used to expect the allowable load of lightweight composite panels.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.59-66
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• 2015

A new concept of an inorganic foaming process at low temperature was demonstrated for the production of inorganic thermal insulating materials with the properties of flexible light-weight, the advantages of organic-based thermal insulation material. The foaming process was proceeded by establishing a skeleton of the foam body by using inorganic fibrous sepiolite and aluminum silicate. A cavity was formed by the expansion of fibrous skeleton body, by the gas which was generated from foaming agent at low temperature. Then the multi-vesicular expanded perlite with low thermal conductivity was filled into the cavity in a skeleton of the foam body. Finally through these overall process, a new inorganic foamed body could be obtained at low temperature without the hot melting of inorganic materials. In order to achieve this object, various preparations such as fibrous sepiolite fibrillation process, heat treatment process of the fibrous slurry were needed, and the optimal compositional condition of slurry was required. The foam body produced showed the properties of flexible light-weight thermal insulation materials such as bulk density, yield strength, flexural strength, and high heat resistance.

• Composites Research
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• v.36 no.3
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• pp.230-240
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• 2023

The deployable reflector antenna consists of 24 unit main reflectors, and is mounted on a launch vehicle in a folded state. This satellite reaches the operating orbit and the antenna of satellite is deployed, and performs a mission. The deployable reflector antenna has the advantage of reduce the storage volume of payload of launch vehicle, allowing large space structures to be mounted in the limited storage space of the launch vehicle. In this paper, structural analysis was performed on the main reflector constituting the deployable reflector antenna, and through this, the initial conceptual design was performed. Lightweight composite main reflector was designed by applying a carbon fiber composite and honeycomb core. The laminate pattern and shape were selected as design variables and a design that satisfies the operation conditions was derived. Then, the performance of the lightweight composite reflector antenna was analyzed by performing detailed structural analysis on modal analysis, quasi-static, thermal gradient, and dynamic behavior.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.34-40
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• 2005

Most analyses and researches on Micro Aerial Vehicle(MAV) have focused upon propulsion, automatic control, aerodynamic configuration in low Reynolds number region, and miniaturization of telemetric parts. In the present study, a structural concept for MAV is designed by using the composite material suitable for light flight structures. In order to study the load path and stress state of the MAV, the load and structural analyses are simultaneously performed by the aeroelasticity module of MSC/NASTRAN. The stability derivatives of the MAV are obtained for three symmetric, two antisymmetric, and four unsymmetric maneuvering conditions. Although the aerodynamic theory in MSC/NASTRAN could not be proper for MAV analysis, it provides an traditional and effective tool for trim and load analyses and may be corrected with the results by more accurate theory or test. The results show that the inertial load due to payloads has a more effect on stress rather than the aerodynamic load.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1377-1380
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• 2010

본 연구에서는 해양준설퇴적물의 유효활용을 위한 역학적, 환경적 실험을 통한 건설재료로서의 활용성을 검토하였다. 울산 방어진과 진해 행안만에서 수거한 준설토로 고화처리토 및 경량혼합토 공시체를 제작하여 압축특성 및 응력-변형 거동 등 공학적 실험을 실시하였다. 해양오염토 유효활용을 위한 활용방법도 예시하였다.

• Journal of the KSME
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• v.27 no.5
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• pp.392-398
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• 1987

새로운 자동차 개발의 목적은 무엇보다도 경량화를 통한 에너지 절약에 기여하는데 있다. 우 리나라는 에너지 자원이 절대 부족하고 특히 석유는 전량 수입에 의존하고 있는 상황이므로 에 너지 절약을 위한 연구가 절대 필요함은 재론의 여지가 없다. 선진국과 같이 우리나라도 경량 복합재료 자동차 개발이 요구되며, 이것은 결과적으로 작금의 자동차의 수출을 계속 유지시킬 수 있는 계기를 만들어줄 것이다. 그러나 현 단계에서 국내의 복합재료 기술수준은 대단히 미약 하나 최근 정부도 이 분야에 적극적으로 연구비를 지원하고 있음은 다행한 일이다. 국내의 자 동차 수요도 점진적으로 증가하고 있고 또한 수출도 이루어지고는 있으나 국내의 시장이 좁은 점을 고려하여 국내의 관련 자동차 메이커는 유럽 공동체 국가들이 수행하는 공동 연구비 투자 방식에 의한 연구 결과를 각 메이커가 적절히 활용함이 바람직하리라 본다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.49-52
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• 2002

경량 건축소재는 건축자재의 경량화, 고급화 및 다양화 등의 기능성 건축소재로서 역할을 요구하고 있으며 그 중 대표적인 것으로서는 polyurethane foamd, Cellulose, 무기 fiber 등이 건축소재로 이용되고 있다. Cellulose계의 wood material의 경우 건축폐재, 가로수의 전지나무 및 제재공장에서 발생하는 나무쓰레기, 대패밥 등과 폐신문지 등의 가공 후 폐기물이 발생하고 있으며 이러한 Cellulose계의 물질들은 고유한 습기의 조절능력, 단열특성을 가지고 있으나 Combustibility, rotting, warping 등의 단점을 가지고 있다 이러한 단점을 극복하기 위해 현대생활환경에 접근할 수 있는 새로운 cellulose계의 modification 및 기술적으로 많이 연구되어지고 있다.(중략)