• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.27-34
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• 2004

Tail-wing, gondola and thrust motor mount(EMS) were built by carbon/glass fiber composites. Structural strength & stiffness was verified by specimen tests. Static strength tests for each structural components were conducted separately. Boundary conditions are specially designed for each components to simulate exact joint conditions. Tests shows no detriment deformation at 100% DLL and no failure at 150% DLL.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.7
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• pp.575-580
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• 2007

During the conceptual design phase of a canard type high maneuverable aircraft, the low speed small scale wind tunnel test was conducted to investigate the high angle-of-attack static stability of the aircraft. In this study, 1/50th scale generic canard-body-wing model was used for the small scale wind tunnel test. For the analysis of static stability including high angle-of-attack nonlinear characteristics, the vertical tail effects were studied due to canard deflections. In addition, the nose chine effects were studied at high angle-of-attack. Based on the results obtained from the experimental study, the configuration change effects for canard type aircraft on high angle-of-attack static stability have been able to analyze.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.357-360
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• 2008

This study was performed to estimate the workability and the static behavior for Bi Prestressed Concrete Girder(Bicon girder) which could introduce effectively prestressed forces into concrete girders. A bicon girder is manufactured by means of introducing pure bending moment that prestress simultaneously the compressive member(steel bar) and the tensile member(steel tendon). Static test was executed for 20m railway bridge girder specimen and evaluated whether pure bending moment was introduced or not, and the behaviors after cracking, and at the ultimate load. Test results showed that a bicon girder had the enough safety in the introduction of pure moment, the serviceability, and the ultimate behavior.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.26-34
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• 2018

Structural static test and the performance test were conducted to determine whether the propeller developed for a multi-copter with the take-off weight of 25 kg satisfies the design requirement. The result of the structural test revealed that the propeller had a safety margin of 3 or more as the ultimate load and requirement load did not cause the specimen breakage. In the performance test, the propeller generated the hover thrust and maximum thrust of design requirement, and hover efficiency in the operating thrust range was greater than 0.73. Maximum hover efficiency increased by more than 3% compared to the reference propeller and electric power consumption decreased by more than 4% in the operating range. The propeller was found to be successfully developed based on the satisfaction rate of the structural strength requirement and the performance requirement.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.11-18
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• 2007

A laboratory investigation was conducted to characterize the flexural fatigue behavior of high performance fiber reinforced cement mortar. Five specimens for statics flexural test and fourteen specimens for the flexural fatigue test were made based on the fiber mixing ratio. Static flexural tests were firstly performed to obtain magnitudes of static failure loads and stress levels before flexural fatigue tests. The flexural fatigue behaviors were investigated based on the stress level and fiber mixing ratio. Also, the equations for the interrelation of the flexural fatigue stress levels with the number at loading cycle were proposed.

• Computational Structural Engineering
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• v.2 no.3
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• pp.77-84
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• 1989

Small-scale models of reinforced concrete beam-column joints and anchorage-bond specimens were subjected to large cyclic displacements at two rates. To assess damage, free vibration tests were conducted. The reliability of the modeling techniques was established by comparison of the results for the slower rate with those obtained from the full-scale tests on prototype. The higher rate of loading caused a greater damage than that at the slower rate. This was evidenced by the measurements of the stiffness obtained from the free-vibration test. The relatively greater extent of damage appears to result from the different bond behavior at different rates of loading.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2C
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• pp.73-80
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• 2006

The shear behavior of four different interfaces consisting of four types of geosynthetics was investigated, and both static and dynamic test for the geosynthetic interfaces were conducted. The monotonic shear experiments were performed by using an inclined board apparatus and large direct shear device. The interface shear strength obtained from the inclined board test was compared with calculated values from large direct shear tests. The comparison results indicated that direct shear tests show high possibility to over-predict the shear strength in the low normal stress range where direct shear tests are not performed. Curved failure envelopes were also obtained for interface cases where two static shear tests were conducted. By comparing the friction angles measured from three tests, i.e. direct shear, inclined board, and shaking table test, it was found that the friction angle might be different depending on the test method and normal stresses applied in the research. Therefore, it was concluded that the testing method should be determined carefully by considering the type of loads and the normal stress expected in the field with using the geosynthetic materials installed in the site.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.146-156
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• 2007

In this paper, the TVC actuation test and analysis results for a flexible seal kick motor nozzle are presented. A real-sized test model of KSLV-I kick motor system is applied to water pressurizing TVC tests which investigate the property changes in TVC nozzle expansion and TVC actuation performance against chamber pressure changes. The equipments which are required for TVC actuation tests are briefly explained. The TVC actuation tests are firstly accomplished in static mode, which reveals TVC error characteristics including thrust misalignment, control accuracy, and TVC stroke increase, etc. The properties in frequency domain is given via dynamic tests. These results may play an important role in enhancing the TVC control performance of KSLV-I.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.15-21
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• 2011

It is required to accumulate experimental datum that make the theories easy to general technicians in order to use composite material widely on construction field. Therefore, we intend to present base technologies that evaluate static and fatigue performance according to the FRP deck section and offer the basis datum for FRP deck analyses and the design standards. As results of static tests, it can be shown that specimen with fabric direction has higher rigidity than that with normal to fabric direction and convergence for the datum. Due to this reason, it has more stable behavior by structural characteristics of matrix arrangement during destruction. For the fatigue tests, we found that by increasing the number of test repetition, test specimen with fabric direction had an crack just before the destruction, and the contact surface was detached.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1854-1866
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• 1997

This paper proposes a new test case generation technique for a nondeterministic finite state machine by improving the existing UIO sequence generation method. First, a new conformance relationis defined, which is one of prerequisites for automatic test case generation. Because fof the nondeterministic property of torpocols, the output of the systems under test is not known deterministically to the tester. Therefore, tree-like test case generation method is introduced for adaptive testing, in which the next input is selected after observing the previous output. Since the test cases are generated with regarding the inputs and outputs as separate events and are represented in tree notation, the test cases are easily converted into TTCN, the international standard test suite specification language.