• 제목/요약/키워드: Noise and vibration-free

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원판이 결합된 외팔 원통셀의 고유진동 특성해석 (Free Vibration Analysis of Clamped-Free Circular Cylindrical Shells with Plate Attached at Arbitrary Axial Positions)

  • 임정식;이영신;손동성
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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    • pp.237-242
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    • 1996
  • A theoretical formulation for the analysis of free vibration of clamped-free cylindrical shells with plates attached at arbitrary axial positions was derived and it was programed to get the numerical results which yield natural frequencies and mode shape of the combined system of plate and shells. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS as well as modal test in order to validate the formulation. The effects of the thickness and location of the plate were evaluated.

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내부에 길이방향 사각판이 부착된 원통셸의 자유진동 해석 (Free Vibration Analysis of Circular Cylindrical Shells with Longitudinal, Interior Rectangular Plate)

  • 이영신;최명환;류충현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.205-210
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    • 1997
  • The analysis of the free vibrations of a circular cylindrical shell with a logitudinal, interior rectangular plate is performed. The natural frequencies and the mode shapes of the combined shells are experimentally obtained by impact testing using an impact hammer and an accelerometer. The effects of the position of the plate on the frequencies and mode shapes of the combined system are examined. The experimental results are compared with a finite element analysis and show good agreement.

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직교좌표계에서 곡선보의 자유진동 해석 (Free Vibration Analysis of Curved Beams in Cartesian Coordinates)

  • BYOUNG KOO LEE
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.47-55
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    • 2003
  • Curved beams are one of the most important basic structural units as well as the beams, columns and plates. Most complicated structures consist of only these basic units and therefore it is very attractive research subject to analysis both the static and dynamic behavior of such units including the arches. The problems of free vibrations of curved beams have been the subject of much work due to their many practical applications.(an ellipsis)

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끝단 질량과 일반적인 단부조건을 갖는 변단면 보의 자유진동 (Free Vibrations of Tapered Beams with General Boundary Conditions and Tip Masses)

  • 오상진;이병구;박광규;이종국
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.802-807
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    • 2003
  • The purpose of this paper is to investigate the free vibration characteristics of tapered beams with translational and rotational springs and tip masses at the ends. The beam model is based on the classical Bernoulli-Euler beam theory. The governing differential equation for the free vibrations of linearly tapered beams is solved numerically using the corresponding boundary conditions. Numerical results are compared with existing solutions by other methods for cases in which they are available. The lowest three natural frequencies are calculated over a wide range of non-dimensional system parameters: the translational spring parameter, the rotational spring parameter, the mass ratio and the dimensionless mass moment of inertia.

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변화폭 원호형 띠기초의 자유진동 (Free Vibrations of Circular Strip Foundations with Variable Breadth)

  • 이병구;허영;이종국
    • 한국소음진동공학회논문집
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    • 제14권3호
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    • pp.230-235
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    • 2004
  • This paper deals with the free vibration analysis of circular strip foundations with the variable breadth. Taking into account effects of both rotatory inertia and shear deformation, differential equations governing free vibrations of such foundations are derived. The Winkler foundation is chosen as the model of soil foundation. The breadth of strip foundation is assumed to be a linear function. The differential equations are solved numerically to calculate natural frequencies. In numerical examples, the strip foundations with the hinged-hinged, hinged-clamped. clamped-hinged and clamped-clamped end constraints are considered. The parametric studies are conducted and the lowest four frequency parameters are reported in figures as the non-dimensional forms.

일반적인 단부조건을 갖는 보의 자유진동 (Free Vibrations of Generally Restrained Beams)

  • 신성철;김봉규;안대순;김선기
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.864-869
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    • 2003
  • The purpose of this paper is to investigate the free vibration characteristics of tapered beams with translational and rotational springs and point masses at the ends. The beam model is based on the classical Bernoulli-Euler beam theory which neglects the effects of rotatory inertia and shear deformation. The governing differential equation for the free vibrations of linearly tapered beams is solved numerically using the corresponding boundary conditions. Numerical results are compared with existing solutions by other methods for cases in which they are available. The lowest four natural frequencies are calculated over a range of non-dimensional system parameters.

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일정체적 캔틸레버 아치의 자유진동 (Free Vibrations of Cantilever Arches with Constant Volume)

  • 이병구;이태은;윤희민
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.1169-1172
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    • 2007
  • This paper deals with the free vibrations of cantilever arches with constant volume. Its cross-sectional shape is the regular polygon whose depth is varied with the linear functional fashion. The non-dimensional differential equations governing the free vibration of such arch are derived and solved numerically for calculating the natural frequencies. As the numerical results, the effects of arch parameters such as side number of cross section, section ratio and aspect ratio on the natural frequencies are reported in figures.

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비균질 탄성지반 위에 놓인 곡선보의 자유진동 (Free Vibrations of Curved Beams on Non-homogeneous Elastic Foundation)

  • 이병구;이태은
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.989-993
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    • 2001
  • This paper deals with the free vibrations of horizontally curved beams supported by non-homogeneous elastic foundation. Taking into account the effects of rotatory inertia and shear deformation, differential equations governing the free vibrations of such beams are derived, in which the linear elastic foundation is considered as the non-homogeneous foundation. Differential equations are solved numerically to calculate natural frequencies. In numerical examples, the parabolic curved member is considered. The parametric studies are conducted and the lowest four frequency parameters are reported in tables and figures as the non-dimensional forms.

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전달강성계수법과 유한요소법의 조합에 의한 사각평판의 자유진동해석 (Free Vibration Analysis of Rectangular Plates by the Combined Transfer Stiffness Coefficient Method and Finite Element Method)

  • 문덕홍;최명수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.353-358
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    • 1998
  • In general, we have used the finite element method(FEM) to find natural frequencies of plates. In this method, however, it is necessary to use a large amount of computer memory and computation time because the FEM requires many degrees of freedom for finding natural frequencies of plates correctly. Therefore it was very difficult to analyze the free vibration of plates correctly on personal computer. For overcoming this disadvantage of the FEM, the authors have developed the finite element-transfer stiffness coefficient method(FE-TSCM) which is based on the concept of modeling techniques in the FEM and the transfer of the stiffness coefficient in the transfer stiffness coefficient method. In this paper, we formulate free vibration analysis algorithm of rectangular plates using the FE-TSCM. Some numerical examples of rectangular plates are proposed, and their results and computation times obtained by the FE-TSCM are compared with those by the FEM and the finite element-transfer matrix method in order to demonstrate the accuracy and efficiency of the FE-TSCM.

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외팔보 구조물의 진동감쇠를 위한 동흡진기의 실험적 연구 (An Experimental study on the Vibration absorber for vibration attenuation of cantilever beam structure)

  • 곽동기;배재성;황재혁;김헌수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 춘계학술대회 논문집
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    • pp.627-632
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    • 2011
  • This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.

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