• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.7-18
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• 2012

Full-scale static test was introduced for the KC-100 aircraft which is domestic civil aircraft to be certified for the first time. Test requirement, test frame, and important test stystems such as loading system, counterbalance system, restraint system and jacking system are explained in detail. Especially, the way to satisfy compliance for the installation of test article and loading system is introduced by using check sheets for the installations. 15 Full-scale and 7 local test conditions were successfully completed and the test data was obtained.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.376-381
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• 2010

The structural strength tests are usually performed to evaluate the structural strength and to verify the structural design and analysis of the vehicle structures. In this paper, the development of a compressed loading type apparatus to load distributed force over the surface of vehicle structure subjected to external loads was described. This apparatus is for structural materials which are easily to fail because of concentrated stresses. This apparatus can apply loads to specimens without any damage on the test specimen's surfaces by using flexible membrane and can be applicable to several kinds of surface profile of structures. The structural strength tests for the flat structure and curved structure with this apparatus were successfully performed, and the test results showed that this type of loading apparatus can be adequate to verify the structural integrity of the fragile structures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.1
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• pp.33-39
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• 2015

This paper describes test result of the Supersonic Wing Structure and the utility of thermal test equipment, which is possible to heat rapidly and continuously above $1,000^{\circ}C$, the durability and reliability of which are improved compared with the existing equipment. Through the test, we could predict the amount of strength reduction of the wing due to aerodynamic heating, caused by exposure of high temperature. Recently the aerodynamic heating temperature of the supersonic flying object is rapidly increased. It is possible to carry out the High Temperature Strength Test on the hypersonic speed flying object with the newly designed thermal test equipment. Because of that, we can upgrade the High Temperature Strength Structure Test technique and test reliability.

• 한국항공운항학회:학술대회논문집
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• 2007.12a
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• pp.76-79
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• 2007

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.6
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• pp.83-91
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• 2005

This paper describes the structural strength test technique and the results for cylindrical supersonic vehicle subjected to both aerodynamic load and thermal load. The special positioning system using spring links was designed to float, support and restrain the test airframe during the test and the down-time. The hydraulic system and the electric heating system were utilized to apply the aerodynamic load and the thermal load to the test airframe together. Particularly, several hundreds of infrared quartz lamps were used for the heating system, and the thermal test conditions were successfully simulated. The test results showed that this kind of high temperature test is adequate to verify the structure integrity and produce useful engineering data which is necessary for the possible structural modification under thermal environments.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.4
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• pp.368-374
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• 1984

본 연구에서는 실험모델인 종의 동적 특성의 실험수행에 편리한 형격햄머법이 이용되었다. 그리고 실험결과의 분석은 F.F.T(Fast Fourier Transform)장치를 이용 하였으며 하중부가효과를 조사하기 위해서 적은 진동수의 변화를 찾아낼 수 잇는 rap- icorder를 이용하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1179-1189
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• 2015

Continuous welded rail on bridge structure experiences typically a large amount of additional longitudinal axial forces due to longitudinal track-bridge interaction under temperature and traction/braking load effect. In order to reduce the additional axial forces, special type of fastener, such as ZLR and RLR or rail expansion joint should be applied. Sliding slab track system is known to reduce the effect of track-bridge interaction by the application of a sliding layer between slab track and bridge structure. This study presents track-bridge interaction analysis results of the sliding slab track and compares them with conventional fixed slab track on bridges. The result shows that the sliding slab track can significantly reduce the additional axil forces of the continuously welded rail, and the difference is more significant for long and continuous span bridge.

• Journal of Aerospace System Engineering
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• v.12 no.1
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• pp.1-9
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• 2018

In this study, a hybrid control method that adjusts for the existing force control technique has been presented for consideration. The proposed hybrid control technique does away with the chattering phenomenon occurring in existing force control technique and provides high shock absorption efficiency. In order to design the controller for the landing gear with MR damper, the equation of motion of the landing gear was derived. The hybrid controller was designed after constructing a simulation model using Recur-Dyne, multi-body dynamic analysis software. The hybrid controller can reduce the maximum strut force and displacement based on the skyhook controller, and is able to get the high efficiency by making it work for the additional force control technique. In addition, an effective switching control technique and input shaping technique was applied to prevent the chattering in the drop simulation. Finally, the performance of the landing characteristics was evaluated throughout the various drop simulations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.881-885
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• 2006

Rain-wind induced cable vibration can cause serious problems in cable-stayed bridges. Externally attached dampers have been used to provide an effective means to suppress the vibration of relatively short stay-cables. For very long stay-cables, however, such damper systems are rendered ineffective, as the dampers need to be attached near the end of cables for aesthetic reasons. This paper investigates a new control system to mitigate the cable vibration. The proposed control system which consists of a laminated rubber bearing and an internal damper may be installed inside of the cable anchorage. A simple analytical model of the cable-damper system is developed first based on the taut string representation of the cable. The response of a cable with the proposed control system is obtained and then compared to those of the cable with and without an external passive damper. The proposed stay-cable vibration control system is shown to perform better than the optimal passive viscous damper, thereby demonstrating its applicability in large cable-stayed bridges for mitigation of rain-wind induced vibration of stay-cables.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.557-563
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• 2007

Rain-wind induced cable vibration can cause serious problems in cable-stayed bridge. External dampers attached to the cables have become widely accepted as an effective means for stay-cable vibration suppression. For very long stay-cables, however, such damper systems are rendered ineffective, as the dampers need be attached near the end of cables for aesthetic reasons. A recent study by the authors proposed that a movable anchorage system is replaced direct fixed support of the cable with a support through a bearing and damper. This paper extends the previous work by adding active control system to mitigate the cable vibration. The response of a cable with the proposed active control system is obtained and then compared to those of the cable with and without an external passive damper. The results show that the active control system can provide superior protection than the passive control system for a cable vibration.