• Title/Summary/Keyword: Vibration Environmental Test

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Shaking Table Test of Steel Cylindrical Liquid Storage Tank Considering the Roof Characteristics

  • Bae, Doobyong;Park, Jang Ho
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1167-1176
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    • 2018
  • Steel cylindrical tanks are widely used for the storage of hazardous substances of which leakage must be prevented under any circumstances. However, the dynamic response of the steel cylindrical liquid storage tank depends sensitively on the fluid-structure interaction and the vibration of the tank structure and necessitates clarification for the safety of the tank structure. This paper presents the results of shaking table tests performed to examine the dynamic behavior of a scaled cylindrical steel tank model considering the presence or not of fixed roof and added mass at the top of the tank for various fluid levels. The test results confirm the occurrence of both beam-type and oval-type vibration modes and show that the larger content of liquid inside the container amplified the acceleration along the height of the cylindrical tank. The oval-type vibration modes are seen to be more dominant in case of large water-to-structure mass ratio.

ENVIRONMENTAL TEST OF THE EQM PAYLOAD SYSTEM FOR THE COMMUNICATIONS AND BROADCASTING SATELLITE

  • Choi Jang Sup;Park Jong Heung;Eun Jong Won;Lee Seong Pal
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.368-371
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    • 2004
  • ETRI has developed the EQM (Engineering Qualification model) payload system for the communications and broadcasting satellite (CBS) with Korean local companies. This paper describes a series of environmental tests such as vibration, thermal/thermal vacuum, and EMC tests. All the development processes including the design, implementation, integration and workmanship were verified and evaluated by these tests. The results of the functional tests and the compliance to the requirements are also presented. The technologies and heritage obtained from this development will be applied to the development of the payload system for the Korean communication satellite in the near future.

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A Case Study of Analysis and Evaluation of Vibration by Construction of Cast in Place Concrete Pile in the Neighboring Areas of Heunginjimun (흥인지문 인접 CIP공사시 진동 전달 특성 분석 및 평가 사례 연구)

  • Choi, Jae-Sung;Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.9
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    • pp.870-878
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    • 2012
  • This paper analysed the effect on Heunginjimun of ground vibrations due to C.I.P. works during Heunginjimun restoration period. Vibration criteria and laws for historic structures was investigated. The vibration was measured under test construction in the field, analysed and evaluated. Because the ground vibration exceeded the vibration criteria, the restoration construction could not be go along. But as vibration was transferred to the upper structures, it was confirmed that vibration levels declined, because of differences between natural and forced frequencies. If the natural frequencies database of historic structures are established, it will help with management and preservation of cultural properties by an environmental vibration effects evaluation.

Shock Separation Test of KOMPSAT-II (다목적 실용위성 2호 충격 분리 시험)

  • 우성현;김홍배;문상무;김영기;김규선
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.1000-1005
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    • 2003
  • The shock separation test simulates the environmental effects of the spacecraft separation from launch vehicle. The shock separation test for a structural model of KOMPSAT-Ⅱ(Korea Multi-Purpose SATellite Ⅱ) was performed in SITC(Satellite Integration & Test Center) launch environmental test hall at KARI(Korea Aerospace Research Institute) to verify the shock test requirement of the spacecraft, to predict the induced acceleration responses on the primary structures and payloads by the explosion of pyre-lock and to perform mechanical fit check. The spacecraft with S/A was mated vertically to LV(Launch Vehicle) adapter simulator via a clamp band, then hoisted and suspended above a foam test bed by four isolation springs secured to the spacecraft hoist fittings to isolate the payload platform shock wave from the sling elements. For separation process, real pyre-devices were used and the time response signals from 60 accelerometers installed on the interested points was acquired and recorded. The SRS responses for each response channels were calculated and the achieved SRS's on the separation plane was reviewed and evaluated in comparison to the ICD(Interface Control Document) value.

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Reliability Analysis of Auto-Connector in Use-condition (사용 조건하에서의 자동차용 커넥터 신뢰성 분석)

  • 김종걸;김진환
    • Proceedings of the Safety Management and Science Conference
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    • 2004.05a
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    • pp.129-136
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    • 2004
  • Environmental factors for automotive consist of temperature, humidity, vibration(sine & random), gas, an electrical load and so on. These environmental factors are impressed in a automotive. Dependability is essential requirement in many electronic parts. Among components of automotive, the connector connecting electrical signals is one of the most important parts. Automotive -connector is inspected according to each manufacturer's test standard in which dependability should be considered. This paper aims to verify that current test standard is suitable for dependability, and present an inductive life test for automotive connector based on the field data in use-condition.

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Analysis of Ground Vibration Characteristics by Test Blasting in Southern Region of Jeju (제주 남부지역의 시험발파에 의한 지반진동 특성 분석)

  • Kim, Seung Hyun;Lee, Dong Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.3
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    • pp.419-429
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    • 2019
  • The characteristics of ground vibration have been analyzed by test blasting in southern region of Jeju (layered ground consisting of basalt and clinker). By grasping the principal component of ground vibration and depriving the prediction equations of ground vibration, the propagation characteristics of ground vibration have been compared to the domestic design guidelines. Ground vibration in layered ground has a small amplitude at a short distance. However, it has been confirmed that the vibration energy is transmitted further by virtue of the low attenuation of the ground vibration as it goes to a longer distance. Moreover, the frequency has been confirmed to be low frequency band. The outcome has been defined that it resulted because the clinker layer with a large pore transforms the blasting energy seismic wave with high frequency into a low frequency wave having a long waveform period. In addition, the limits of design guidelines were identified by comparing the ground vibration of Jeju and other bedrock areas. Thus, the necessity of the development of the prediction equations of ground vibration utilized in design that reflect the characteristics of the area has been suggested.

Enhancing maintenance performance of tunnel drainage using vibration from polyvinylidene fluoride(PVDF) film (압전필름의 진동을 활용한 터널배수재 유지관리 성능 개선)

  • Xin, Zhen-Hua;Moon, Jun-Ho;Song, Young-Karb;Kim, Young-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.822-826
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    • 2015
  • This study investigated the possible use of vibration from polyvinylidene fluoride(PVDF) film to enhance the performance of the deteriorated tunnel drainage due to physical/chemical clogging of the fine particles through a series of laboratory experiments. The test program was consisted of two different experiments, fundamental investigation and drainage model test. In the fundamental investigation, flow of clay slurry mixed with 50% water (freshwater and brine) on PVDF film with various frequencies was examined. In the model tests, slurry clogging to the woven fiber attached to drainage pipe and its reduction by vibration was investigated. Results of the experiment show that vibration from PVDF film enhances the drain performance significantly. Based upon the investigation, it gives an essential data that are needed for a potential use of hybrid drainage system with PVDF.

Experimental Approach Method for Strcutural Dynamic Modification of Vibration Test Fixture (진동시험치구의 구조변경을 위한 실험적 접근법)

  • 김준엽;정의봉
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.04a
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    • pp.100-105
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    • 1996
  • This paper proposes the method of experimental structural dynamic modification of fixture for environmental vibration test control. This method can predict the responses at any points on fixture utilizing the experimental data, and structural dynamic modification of fixture is made using the predicted responses for the spectra at the speciment attachment points to meet the specified reference spectrum. From the results of controlling the fixture before and after modification by conventional control method and optimal reference spectrum, which has been previously reported by the authors, the proposed method is shown to be an effective one.

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Experimental investigation of vortex-induced aeroelastic effects on a square cylinder in uniform flow

  • Huang, Dongmei;Wu, Teng;He, Shiqing
    • Wind and Structures
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    • v.30 no.1
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    • pp.37-54
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    • 2020
  • To investigate the motion-induced aeroelastic effects (or aerodynamic feedback effects) on a square cylinder in uniform flow, a series of wind tunnel tests involving the pressure measurement of a rigid model (RM) and simultaneous measurement of the pressure and vibration of an aeroelastic model (AM) have been systematically carried out. More specifically, the aerodynamic feedback effects on the structural responses, on the mean and root-mean-square wind pressures, on the power spectra and coherence functions of wind pressures at selected locations, and on the aerodynamic forces were investigated. The results indicated the vibration in the lock-in range made the shedding vortex more coherent and better organized, and hence presented unfavorable wind-induced effects on the structure. Whereas the vibration in the non-lock-in range generally showed insignificant effects on the flow structures surrounding the square cylinder.