• 제목/요약/키워드: free-vibration modes in air

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유체로 연성된 두 사각평판의 고유진동수 (Natural Frequency of Two Rectangular Plates Coupled with Fluid)

  • Jeong, Kyeong-Hoon;Park, Keun-Bae
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.389.1-389
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    • 2002
  • An analytical study is presented on the hydroelastic vibration of two rectangular identical plates coupled with a bounded fluid by using the finite Fourier series expansion method. It is observed that the two contrastive modes, the so called the out-of-phase and in-phase modes. All natural frequency of the in-phase modes can be predicted well by the combination of the beam modes in the air, but the natural frequency of the out-of-phase mode cannot be estimated precisely. (omitted)

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대형부체구조물(大型浮體構造物)의 유(流).탄성(彈性) 연성거동에 관한 실험적 고찰 (A Experimental Study on the Hydroelastic Behavior of Large Floating Offshore Structures)

  • 이상엽
    • 한국공간구조학회논문집
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    • 제1권2호
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    • pp.101-110
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    • 2001
  • A large floating structure is attracting great attention in recent years from the view of ocean space utilization. Its huge scale in the horizontal directions compared with the wavelength and relatively shallow depth make this type of floating structure flexible and its wave-induced motion be characterized by the elastic deformation. In this paper, a boundary integral equation method is proposed to predict the wave-induced dynamic response mat-like floating offshore structure. The structure is modeled as an elastic plate and its elastic deformation is expressed as a superposition of free-vibration modes in air. This makes it straightforward to expand the well-established boundary integral technique for rigid floating bodies to include the hydroelastic effects. In order to validate the theoretical analysis, we compare with the experimental result of reduced model test. Satisfactory agreement is found between theory and experiment.

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대형부체구조물(大型浮體構造物)의 유체(流體)·탄성체(彈性體) 연성거동의 이론적 해석에 관한 연구(硏究) (A theoretical study on the hydroelastic behavior of Large floating offshore structures)

  • 이상엽;나용호
    • 한국산업융합학회 논문집
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    • 제4권4호
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    • pp.433-439
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    • 2001
  • A large floating structure is attracting great attention in recent years from the view of ocean space utilization. Its huge scale in the horizontal directions compared with the wavelength and relatively shallow depth make this type of floating structure flexible and its wave-induced motion be characterized by the elastic deformation. In this paper, a boundary integral equation method is proposed to predict the wave-induced dynamic response mat-like floating offshore structure. The structure is modeled as an clastic plate and its elastic deformation is expressed as a superposition of free-vibration modes in air. This makes it straightforward to expand the well-established boundary integral technique for rigid floating bodies to include the hydroelastic effects. In order to validate the theoretical analysis, we compare with the experimental result of previous model test. Satisfactory agreement is found between theory and experiment.

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승용차용 레이디얼 타이어에서 공기공동진동형이 구조진동형에 미치는 영향에 관한 실험 (Experiments on the Influence of the Air Cavity Resonance on the Structural Vibration Modes in Radial Tire)

  • 김용우;정경신
    • 한국자동차공학회논문집
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    • 제15권6호
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    • pp.44-49
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    • 2007
  • It is well known that the acoustic cavity inside the tire-wheel assembly contributes to vehicle interior noise. In this paper, we have performed acoustic and structural modal testings to investigate the influences of the acoustic cavity resonance on structural vibration characteristics for the tire in free-suspension and for the loaded tire. The testings have given us some findings, which are reported in this paper.

유공직사각형평판(有孔直四角形平板)의 접수진동(接水振動) (Transverse Vibration of Rectangular Plates Having an Inner Cutout in Water)

  • 이호섭;김극천
    • 대한조선학회지
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    • 제21권1호
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    • pp.21-34
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    • 1984
  • This paper is concerned with the experimental investigation of transverse vibration characteristics in water of rectangular plates having an inner free cutout. Systematic experiments are carried out to investigate effects of the surrounding water on the added mass and the natural frequency of the plates due to the changes of the aspect ratio, hole size and eccentricity. The main subject is the clamped rectangular plate with a circular hole. For the purpose of comparative evaluations, some other common-type boundary conditions and hole shapes such as ellipses and rectangles are also investigated. Some of the results obtain are as follows; 1) For each given aspect ratio of the plate, there is a hole area ratio which gives a minimum value of the nondimensional frequency parameter for each mode. The hole area ratio increases as the order number of the mode increases. 2) The nondimensinal mass-increment parameter decreases as the aspect ration or the order number of the mode increases. For each given aspect ratio, the parameter the fundamental mode decreases monotonically as the hole area ratio increase. In cases of the second and higher order modes, however, each mode has a hole area ratio which gives a maximum value of the parameter for each aspect ratio more then 2/3. 3) Comparing elliptic holes with rectangular ones with same hole area ratio, nondimensional frequency parameters are almost same for each given ratio of the shorter axises to the longer one. 4) The influences of difference in boundary condion on nondimensional frequency parameters in water are similar to those in air.

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