• 방재와보험
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• s.42
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• pp.72-75
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• 1989

• Fire Protection Technology
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• s.34
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• pp.48-48
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• 2003

• 방재와보험
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• s.38
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• pp.40-43
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• 1988

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.114.2-114.2
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• 2013

위성체가 임무를 수행하는 우주환경은 지상 환경과 달리 고진공, 고온 및 극저온의 가혹한 환경 이다. 이에 $10^{-5}$ Torr 이하의 고진공과 $-180^{\circ}C$ 이하의 극저온 및 고온의 환경조건을 지상에서 모사하기 위해서는 열진공챔버와 같은 우주환경모사장비가 사용된다. 위성체를 열진공챔버에 설치하고 우주환경모사 시험의 월할한 진행을 위하여 열진공챔버 내 레일을 설치하여 열진공시험 준비 및 열진공시험이 수행되어진다. 현재 위성체 연구개발의 발전으로 다양한 기능 및 장비의 추가로 인하여 위성체가 대형화 되어지고 있다. 이에 보다 안전한 시험 준비 및 수행을 위하여 현재 운용되어지고 있는 열진공챔버의 개선이 필요하다. 이에 본 연구에서는 상용유한요소해석 프로그램 MSC.PATRAN/NASTRAN을 사용하여 대형 위성체의 우주환경모사 시험을 위한 열진공챔버 내 레일에 대한 구조 안선성을 평가 하고자 한다.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.190-200
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• 2007

A pyrogen type igniter was designed to satisfy the requirements of KSLV-I Kick Motor system. To insure the reliability of the igniter before the production of the flight model, we have been performed the structure, environmental, combustion tests. The hydraulic test was carried out to confirm the strength of the components of the igniter. The shock and vibration tests were considered to check whether the igniter operates normally under the severe environmental condition. The combustion tests were also performed to understand the ignition characteristics with the variation of initial condition. Finally, we confirmed that the igniter could provide the acceptable energy to ignite the propellant of kick motor at the ground test.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.25-32
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• 2014

The main objective of materials testing is to simulate in-situ field conditions as closely as possible, including loading conditions, climatic conditions, etc. Also, the test method should be easy, inexpensive, simple, and efficient to conduct to become an acceptable standard laboratory testing method for many agencies. Based on these reasons, a new test method employing repetitive axial loading with confinement was developed to evaluate the rutting(permanent deformation) of asphalt concrete. The new laboratory test protocol was developed based on the study of the various structural analysis and field data. This protocol divides asphalt layer(s) into three categories depending upon the depth. Different temperatures and vertical stress levels were used in these areas.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.5
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• pp.482-489
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• 2010

This paper describes the test procedure, instrumentation, verification methodology and the results of the ground vibration test(GVT) and force vibration test(FVT) of the SmartUAV aircraft to estimate experimentally dynamic characteristics of the aircraft. Bungee cords are used to emulate free-free boundary conditions of the test aircraft. The SmartUAV is excited by three shakers and one-hundred frequency response functions(FRF's) is measured. The FRF's are reduced and analyzed to identify the dynamics parameters of the SmartUAV. To extract modal parameters of the SmartUAV such as, natural frequencies and damping ratios, the poly-reference least square complex exponential method is used in the time domain. The mode shape coefficients are estimated with the least squares frequency domain method to identify the vibration modes. The FVT was performed by fixed sine frequency with three shakers on the x, y and z direction and vibration characteristics of structures and detail equipments are measured.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.81-85
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• 2006

Through-the-thickness properties of thick-walled cylindrical composites are required to determine structural performances because interlaminar tensile stress is primarily responsible for structural failure of the composites during their curing process. It is necessary for evaluating the tensile properties to find individual test methods to find appropriate methods because there are no recognised international standards(test methods and test specifications) available for generating reliable tensile properties in the direction. This paper has performed an experimental Study to measure that properties of carbon fabric/phenolic composites are produced by domestic company. Several test methods using an aluminum specimen were compared and evaluated. The best method, found out, was adopted to measure transverse through-the-thickness properties of composite materials. The results show that strain trends on four faces of composite specimen are the same.

• Journal of Korean Society of Steel Construction
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• v.23 no.4
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• pp.515-522
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• 2011

The purpose of this study was to evaluate the material characteristics of SHN400 steel, which is suitable as a steel material for building structures, using the experimental approach. For this purpose, the chemical composition test, tensile test, macro test, micro test, and charpy notch impact test were conducted with specimens taken from the highest, thickest, and commonly used H-beams for girder or beam members. Each test was conducted under the Korean Standard(KS) test conditions. All the test results satisfied the requirements of KS (KS D 3866) and the steel material for seismic design. The carbon equivalent value (Ceq), which is related to weldability, and the yield ratio, which is related to inelastic behavior, showed especially good results. Thus, SHN400 is definitely suitable as the steel material for building structures.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.5
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• pp.526-531
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• 2003

Condition assessment of concrete structures is essential since their performance affects public safety. Impact resonance testing has been widely used for the nondestructive testing of the concrete structures. In this article, the background, basic principles of the impact resonance testing were described. Not only laboratory studies but also the field applications such as basement concrete of large structure and large slurry wall are described.