• 제목/요약/키워드: vibration

검색결과 25,031건 처리시간 0.043초

디젤기관 추진축계의 연성진동에 관한 연구 (제1보:연성이 고유진동수와 그의 모드에 미치는 영향) (Studies on Coupled Vibration of Diesel Engine Propulsion Shafting)

  • 김의간
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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    • pp.60-71
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    • 2000
  • When the crankshaft of Diesel engine has more than 3 throws which are arranged in a different plane its vibration induces coupled motions especially the coupled torsional and axial vibration. Nowadays the torsional vibration which is influenced rather weak than axial one can be theoretically calculated fairly accurately but theoretical calculation results of the axial vibration which is influenced strongly from torsional vibration is not so good. To get accurate calculation results of axial vibration coupled axial-torsional vibration must be treated. in this investigation coupled effects of vibration of Diesel engine propulsion shafting are analyzed theoretically and some more simple calculation methods are also studied. On this first report effects of coupling on natural frequencies and their modes are mainly studied setting the each mass in 4 degrees of freedom. later this problem may be studied again by setting each mass as 6 degrees of freedom.

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

  • 최재성;민경원
    • 한국소음진동공학회논문집
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    • 제22권9호
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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.

소실모형주조용 진동장치의 성능 평가 (Performance Evaluation of Vibration Table for Lost Foam Casting Process)

  • Lee, Eun-Kyung;Rim, Kyung-Hwa;Lee, Kyung-Whoan
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.322.2-322
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    • 2002
  • Vibration table is required to obtain high packing density in lost form casting process. Packing density, which is important manufacture factor, depends on the vibration pattern induced by vibration table. In general, circular vibration pattern is recognized as the best pattern. The existing vibration table is investigated to identify current vibration pattern and consider a countermeasure. Modal test is utilized to identify the dynamic characteristics of vibration table, and finite element method is used to present the improved design

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지반의 진동전달식 산정에 관한 연구 (A Study on the Calculation of Vibration Transfer Formula for Ground Vibration)

  • 홍갑표;전호민
    • 소음진동
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    • 제8권5호
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    • pp.799-806
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    • 1998
  • Noise and vibration due to railway traffic are major causes of environmental pollution in the city. In course of judging, assessing and coping with the problem, it becomes imperative to predict the vibration level induced by railway traffic passing through downtown in the city. The vibration due to railway traffic is transferred to the neighbouring buildings through the ground. In this study, as a method predicting vibration level of the buildings near railway, a vibration transfer formula is suggested. This formula is used to calculate vibration level occuring at the bottom of the neighbouring buildings, which are located at a certain distance from railway.

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지하철 진동이 구조물에 미치는 영향분석 모델 (MODEL FOR SUBWAY-INDUCED STRUCTURAL VIBRATION)

  • 김희철;이동근;민경원
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1993년도 가을 학술발표회논문집
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    • pp.199-204
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    • 1993
  • Noise and vibration induced by subway operation are one of the major factor that annoying residents living near the. railway. In general, lateral vibration was the major concern when we are considering vibration of the building. Since the energy due to earthquake is enormous it affects wide area. However, the vertical vibration became a major concern in considering the vibration induced by subway because relatively smaller energy affects only nearby areas than that of earthquake. Analysis model of the structure for the vertical vibration should consider the effect of beam vibration. Thus, the model of the structure for the lateral vibration can not be applied. Appropriate analysis model which can consider the inertia force of the beam is necessary when analyzing a structure for the vertical vibration. Modeling technique for the vertical vibration analysis of structures has been studied on this paper. It is recommeneded to use 2 or more elements for columns and to use 3 or more elements for beams when analyzing structures for vertical vibration induced by subway.

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발전소 열교환기에서의 유동유발 진동저감 (Reduction of Flow Induced Vibration in the Heat Exchanger of Thermal Power Plant)

  • 장한기;김승한
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.633-638
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    • 2000
  • This paper reports an example of flow-induced vibration in a very large plant and the whole procedure of reducing the vibration. During the operation of flue gas desurfurization unit of the thermal power plant, serious vibration occurred at all around the unit. The worst vibration was recorded on the heat exchanger surface, which weighed 180 tones, as 17.8 m/$s^2$ in vibration amplitude at 34Hz. To identify the vibration, frequency analysis on the response vibration, the expected excitation force and the system resonance was executed. This investigation revealed that the cause of the vibration was vortex shedding from the circular pipes in the heat exchanger. Vortices from the pipes excited acoustic resonance in the heat exchanger room, which, in turn, made the structure vibrate. Through inserting the baffles between the pipes, which had an effect of cutting the acoustic wave at resonance frequency, the vibration was eliminated dramatically.

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정밀 혐진기기 방.제진을 위한 바닥 진동성능평가에 관한 연구 (Evaluation on the Floor Vibration Characteristics for the Vibration Control of Vibration Sensitive Equipments)

  • 이호범;노병철;조동진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.933-939
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    • 2000
  • In this paper we present an overview of the factors and techniques that must be considered in vibration measurements in the floor structures for microelectronics facilities. Normally narrowband vibration spectrum or equivalent signals are suggested as the guide indexes of site vibration phenomina. But it cannot support perfect informations in designing vibration control systems for the vibration sensitive equipment even though the spectrum serves to illustrate the fact that most real vibration environments are dominated by broadband energy as opposed to tonal energy. The major topics cover stiffness in frequency and time domain, acceleration level and modal characteristics from experimental modal analysis as well as narrowband spectrum. The combined signal analysis through the items mentioned above can give better solutions and would be positively recomended to solve the vibration problems on a sort of limited field.

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열교환기에서의 유동유발 진동 저감 (Reduction of Flow-Induced Vibration in the Heat Exchanger)

  • 장한기;김승한;이재현;양정렬
    • 소음진동
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    • 제9권6호
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    • pp.1200-1209
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    • 1999
  • This paper reports a peculiar example of flow-induced vibration in a very large plant and the whole procedure of reducing the vibration. During the operation of flue gas desurfurization unit of the thermal power plant, serious vibration was dtected at all around the plant. The worst vibration was recorded on the heat exchanger surface, which weighed 180 tones, as 17.8 m/$s^2$ in vibration amplitude at 34 Hz. To identify the vibration, frequency analysis on the response vibration as well as on the expected excitation forces and the system resonance was executed. This investigation revealed that the cause of the vibration was vortex shedding from the circular pipes in the heat exchanger. Vortices from the pipes excited acoustic resonance in the heat exchanger room, which, in turn, made the structure vibrate. Through inserting the baffles between the pipes, which had an effect of cutting the acoustic wave at resonance frequency, the vibration was eliminated dramatically.

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전라선 괴목고가교 방진침목패드 시공 전/후 비교 분석 (Comparison and analysis the Effect of Vibration Control Sleeper Pads on Gwe-Mok Elevated Railway Bridge in Jeolla Line)

  • 엄기영;유원희;김지훈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.924-928
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    • 2002
  • Response of the rail surface is an important factor for the train safety and comfortable travel, and evaluation of vibration at the area along a rail is an important factor for the vibration. The dominant method to reduce the vibration that reach the ground is installing vibration absorber between rall and the under structure. In this paper, we evaluated the vibration reducing effect of using vibration control sleeper pads to slave and earth at certain distance from the sleepers.

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철도교량의 진동측정 및 방진대책 (Measuring the vibration and Vibration control of Railway Bridge)

  • 엄기영;정흥채;한성호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.929-934
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    • 2002
  • There are many reasons for occurring vibration when trains run on the railway, but the typical vibration are occurring when the trains run on the elevated Railway bridge. For the settlement of the problems form the vibration, it must be performed to analyze the effect of the vibration to human bodies and adjacent area. and to establish the countermeasures. In this paper, we analyzed the effects of the vibration to the bridge itself and to adjacent structures by measuring the vibration of Yong-Dang Elevated Railway Bridge on Jeolla Line and adjacent area.

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