• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.777-784
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• 2016

In this study, regulation of the performance test load of a vibration-proof fastening system used in urban railways was established through evaluation of the loads that it bears in the field. In order to investigate the range of the dynamic stiffness of the vibration-proof fastening system, dynamic stiffness tests were carried out for three types of vibration-proof fastening system that can be domestically supplied. Train and track interaction analyses in the frequency domain were carried out to evaluate the dynamic wheel loads. The track irregularity, which is a very important input factor in train and track interaction analysis, was considered as a PSD (Power Spectral Density) function, which was derived based on the measured data. The loads on the vibration-proof rail fastening system were evaluated considering various operating conditions in the urban railway. Regulation of the performance test load of the vibration-proof rail fastening system was established based on the evaluated loads.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.208-216
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• 2004

Advanced overload protection module for full scale airframe structural test was developed by improving the existing overload protection module. When performing the full scale airframe structural test, overload can be applied to the test article due to unexpected situations such as system shutdown, test article failure, and deficiency of design strength. Therefore, the overload protection module is needed for protecting the test article in unexpected overload situations. In this paper, the function of the existing overload protection module was summarized for each component and the problems encountered when using it in structural test were analyzed in addition, the development of advanced overload protection module was described.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.39.1-39.1
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• 2010

본 연구에서는 정하중 및 충격하중 하에서 FRP(fiber reinforced polymer) sheet의 보강 성능을 평가하기 위해 섬유와 레진의 종류, sheet 종류, 보강 방법에 따른 휨 실험을 실시하였다. 이를 위해 GFRP와 CFRP, AFRP sheets로 보강된 $100{\times}100{\times}400mm$ 각주형 콘크리트 공시체의 하면 보강, 중앙 U형 스트립, 그라고 이 둘을 동시에 보강한 시험체를 제작하였고, 정하중 휨 실험과 낙하식 충격하중 실험을 실시하였다. 정하중 실험에서 중앙부 U형 스트립으로 보강한 시험체는 섬유의 방향과 균열의 진전 방향이 일치하여 보강효과가 거의 없었지만 CFRP와 AFRP로 하면 및 이중 보강한 시험체는 높은 휨성능을 보였다. 반면 충격하중 실험에서는 중앙부 U형 스트립 보강이 다소 성능을 향상 시켰고, 하면 및 이중 보강한 시험체는 큰 변형과 높은 에너지 소산 능력을 보였다.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.117-122
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• 2008

Acoustic test was performed to verify the ability of KSLV-I PLF acoustic protection system (Acoustic blanket) to reduce the acoustic load. The test results showed that the acoustic protection system has +3 dB safety margin compared with design requirement. This paper also illustrates the increase of insertion loss by the acoustic protection system by comparing that of the bare PLF structure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.87-92
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• 2005

The permeability of concrete affects largely on the durability of concrete, therefore it is required that the correct assessment and improvement of permeability. Therefore it is rational method that the permeability of concrete structures is estimated in the common use states under loading than in the early sound conditions. In this study, to improve the permeable efficiency of concrete, some kinds of fiber and resin are mixed in making of concrete specimens. And also, for the reasonable assessment of permeability, after 50% and 70% pre-loadings of its compressive strength were acted on the specimens, the tests were executed. From the results of this study, in the case of 50% pre-loading coefficients of permeability were increased about 1.4times against the nonpre-loading specimens and in the case of 70% pre-loading they were increased about 17.8times. And it turned out that hybrid steel fiber reinforcement is most effective for the improvement of permeable efficiency of concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.341-346
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• 2002

이 연구는 게르버 보 형식의 포스트텐션 PC 골조 구조 시스템의 실용화를 위해 골조 전체의 구조 성능 시험을 수행하며, 여기서 보-기둥 접합부 및 내민 보-단순 보 접합부의 구조 성능과 골조의 안전성을 확인한다. 시험은 400 mm$\times$800 mm 단면의 경간 3 m 보와 500 mm$\times$600 mm 단면을 갖는 높이 3 m 기둥의 실물 크기 시험체를 제작하여, 기둥에 80 톤의 축 하중을 준 상태에서 단순 보 중앙에 하중을 가력하여 기둥-보 접합부와 단순 보-내민 보 단면 축소 연결부의 구조성능을 파악한다. 시험 결과, 보 - 기둥 접합부는 예상 설계 하중 40톤 이상에서도 강 접합에 가깝게 거동하였고, 단순 보- 내민 보의 단면 축소 연결부는 경사철근의 사용으로 초기 균열 및 균열 확산에 대한 억제 효과가 있었으며, 예상 설계 전단력 40톤에서 안전하다는 것이 확인되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.956-959
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• 2007

기존 투명방음판용 알루미늄 프레임의 구조적 단점을 보완할 수 있는 강재-FRP(Fiber Reinforced Plastic) 합성단면 구조재를 개발하였으며, 아울러 조립이 간편하고 외부 충격에 의해 쉽게 분리가 되지 않는 삽입형 수평재-수직재 코너연결부 상세를 개발하였다. 개발된 강재-FRP 합성단면 구조재와 코너연결재를 결합하여 프레임을 형성하고 그 사이에 투명패널을 삽입함으로써 길이 4m, 높이 1m 투명방음판 시작품을 완성하였으며, 이렇게 완성된 투명방음판 시작품을 대상으로 KS 4770-1 구조성능 평가시험을 수행하였다. 한국도로공사 교량부 시험하중에 대해 설계된 강재-FRP 합성단면 프레임 투명방음판의 구조성능 평가결과, FRP 의 추가적인 구조강성 증가 효과로 인해 한국도로공사 교량부 시험하중을 약간 상회하는 KS 2 호 등급시험하중까지도 만족시키고 있음을 확인할 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7244-7249
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• 2015

In this study, in order to asses the structural performance of trapezoidal PSC girder using a socket joint system and it is possible to calculate the optimized cross-section of the web element tests were carried out for each specimens. we conducted a socket joint performance test, web bending and shear performance tests and all tests were performed at 4 point loading method. The initial crack load of socket joint specimen was significantly lower than the reference specimen but post peak behavior was no significant differences. And the length of the loop joint of the reinforcing bars had no significant effect on the maximum load. As a web shear tests, to obtain a maximum load of the specimen has a prestressing rod reinforced at tension side. As a web flexural tests, to obtain higher diagonal cracking load in specimen of reinforced using prestressing rod than reference specimen.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.694-702
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• 2017

In the case of an elevated railway station, structure borne noise and vibration due to structural limitations allow the load and vibration from railway vehicles to be directly transmitted to the station structure, resulting in an increase in the number of civil complaints from customers and staff of the station. The floating slab track system, which is well known as one of the solutions for reducing the noise and vibration from elevated railway stations, usually contains rubber mounts or rubber pads under the railway slab which act as a damper. These types of device have the disadvantage that is difficult to predetermine the exact stiffness and damping ratio under the nonlinear loads resulting from train services. In this study, an isolator with a friction type of wedge is introduced, which can be applied to floating slab track systems and to be designed with precisely the required stiffness. Furthermore, a comparative analysis of the stiffness between the designed and experimental values is carried out, while the damping ratio, which is closely related to the friction wedge blocks, is deduced according to the train load condition. The performance tests of the isolator were conducted in accordance with the DIN 45673-7 standard which includes both static and dynamic load tests. The load conditions for the performance tests are designed to conform to the DIN standard related to the weight of the train and rail track, in order to perform vertical and horizontal load tests, so as to ensure the secure structural safety of the railway. Also, by checking the change aspect of the friction coefficients of the friction elements according to the loading rate, the vibration reduction performance of the friction type isolator with variable loading rate conditions is examined.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.395-399
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• 2010

강구조 부재의 내화성능평가를 위한 비재하가열시험은 강재 허용온도로 평가되고 있으나, 강재의 허용온도 설정은 H형강 부재의 최대하중로 평가되는 한계용도와 고온에서의 강소재의 허용응력도 능력으로 설정되었으므로 실지 작용되는 강구조 부재의 하중조건과 다양한 부재의 종류 등의 관점에서 허용온도의 적용은 다소 불합리한 점이 있다고 판단된다. 따라서 본 연구에서는 강구조 건축물에서의 부재에 작용하는 하중에 따른 내화성능의 차이를 보이고 이에 따른 합리적인 내화성능 평가방법을 제안하고자 한다.