• 제목/요약/키워드: Rigid Body Mode

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차량 파워트레인계의 강체고유진동수 민감도 (Eigenvalue Sensitivity of Rigid Body Mode for Vehic1e Powertrain System)

  • 원광민;강구태
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.609-615
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    • 2001
  • In this paper, the eigenvalue sensitivity of vehicle powertrain was investigated by analytic method. The powertrain system was considered as a rigid body with multiple engine mounts, and the engine mounts were supposed as three linear springs in three orthogonal directions. The design parameters for the sensitivity analysis were engine mount properties (positions, stiffness, and orientations) and powertrain properties (mass, second moment of inertia, and center of gravity). Firstly, an effective form of eigenvalue problem for the powertrain system was introduced. Then, the analytic sensitivity of eigenvalue was derived using the equation. Lastly, the derived sensitivity equation was applied to a real powertrain system to provide its correctness and applicability.

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단일 진동체의 진동 흡진기 설계 기법 (Design of a Vibration Absorber for an Elastically Suspended Rigid Body)

  • Kim, Dong-Wook;Park, Yong-Je
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.325.2-325
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    • 2002
  • A new methodology is presented for the multi-degree-of-freedom vibration absorber for an elastically suspended rigid body with the planes of symmetry in general motion. Unlike the common single degree-of-freedom vibration absorber, the presented methodology makes use of both linear and rotational properties of the absorber. It is suggested that an absorber is designed separately for the in-plane and out-of-plane axes of vibration and combined the two cases for a six-degree-of-freedom absorber. (omitted)

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유한요소 모델을 이용한 압축기의 진동특성에 관한 연구 (A Study of vibration Characteristics of Compressors with FEM model)

  • 주정함;황원걸;최기섭;류기오;서문희
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.967-971
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    • 2004
  • Today, as the demands for home appliances are increasing, the understanding of noise and vibration characteristics have become more important. It is hard to control its vibration and noise characteristics, because its mechanical structure is very complex. In this study a model of reciprocating compressor is developed. Spring, frame, and LDT are modeled as flexible body, and the other parts are modeled as rigid. FEM model of frame is simplified in order to save the simulation time. We validated the simple model by comparing their natural frequencies and mode shapes. Motor torque is applied to a rotor, and the piston is subjected to a gas pressure. The vibrational characteristics of compressor is analyzed with LS-DYNA. Its results are compared with the simulation results of rigid body frame. The effect of LDT is also studied by comparing the vibration of frame with the results of simulation with no LDT.

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Dynamic modeling and structural reliability of an aeroelastic launch vehicle

  • Pourtakdoust, Seid H.;Khodabaksh, A.H.
    • Advances in aircraft and spacecraft science
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    • 제9권3호
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    • pp.263-278
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    • 2022
  • The time-varying structural reliability of an aeroelastic launch vehicle subjected to stochastic parameters is investigated. The launch vehicle structure is under the combined action of several stochastic loads that include aerodynamics, thrust as well as internal combustion pressure. The launch vehicle's main body structural flexibility is modeled via the normal mode shapes of a free-free Euler beam, where the aerodynamic loadings on the vehicle are due to force on each incremental section of the vehicle. The rigid and elastic coupled nonlinear equations of motion are derived following the Lagrangian approach that results in a complete aeroelastic simulation for the prediction of the instantaneous launch vehicle rigid-body motion as well as the body elastic deformations. Reliability analysis has been performed based on two distinct limit state functions, defined as the maximum launch vehicle tip elastic deformation and also the maximum allowable stress occurring along the launch vehicle total length. In this fashion, the time-dependent reliability problem can be converted into an equivalent time-invariant reliability problem. Subsequently, the first-order reliability method, as well as the Monte Carlo simulation schemes, are employed to determine and verify the aeroelastic launch vehicle dynamic failure probability for a given flight time.

대칭면을 갖는 강체 진동계의 진동모드에 대한 기하학적 해석 (The Geometrical Mode Analysis of an Elastically Suspended Rigid Body with Planes of Symmetry)

  • 단병주;최용제
    • 대한기계학회논문집A
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    • 제24권1호
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    • pp.110-117
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    • 2000
  • Vibration modes obtained from a modal analysis can be better explained from a screw theoretical standpoint. A vibration mode can be geometrically interpreted as a pure rotation about the vibration center in a plane and as the twisting motion on a screw in a three dimensional space. This paper, presents the method to diagonalize a spatial stiffness matrix by use of a parallel axis congruence transformation. It also describes that the stiffness matrix diagonalized by a congruence transformation, can have the planes of symmetry depending on the location of the center of elasticity. For a plane of symmetry, any vibration mode can be expressed by the axis of vibration. Analytical solutions for the axis of vibration has been derived.

부유식 가두리 양식장의 파랑중 유탄성 응답 해석 (A Hydroelastic Analysis of a Floating Fish Cage in Waves)

  • 최윤락;여환태
    • 한국해양공학회지
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    • 제23권6호
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    • pp.7-11
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    • 2009
  • The dynamic responses and drift forces in waves of a floating circular fish cage are analyzed considering hydroelastic effects. The method of generalized mode is used to calculate the hydroelastic responses of the floater of cage. The elastic mode shapes, generalized mass, and stiffness in dry mode are evaluated by using a structural analysis code. The higher-order boundary element method is adopted to analyze the interaction between fluid and deformable structure. Some results of vertical motions and drift forces are shown and compared with those for a rigid body.

운동방정식 유도에 의한 액추에이터 모드 주파수 분석 (A Mathematical Approach for Modal Frequency Analysis in Actuators)

  • 이경택
    • 한국소음진동공학회논문집
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    • 제23권6호
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    • pp.537-545
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    • 2013
  • In this paper, the vibration for actuators having lens module, confined to lateral and torsional directions of suspensions, is described by mathematically analyzing its suspension configuration and motion. In order to prove the accuracy of this result, it is compared to a finite element analysis. Also it is shown that modal frequencies can be modified by changing design parameters in mathematical motion expressions.

Ramp장치를 이용한 철도차량 거동모드 주파수에 관한 연구 (A Study for behavior mode frequency of railway vehicle using ramp device)

  • 양희주;우관제;성재호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.30-35
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    • 2010
  • The railway vehicle is a multi-body system running on the track which consists of carbody, bogie and wheelset, each of components is connected with rigid mass, spring and damper. each of components has translation motions of longitudinal (X axis), lateral(Y axis) and vertical(Z axis) direction, and rotation motions of X, Y, Z axis which are named Rolling, Pitching and Yawing. The vibration mode of railway vehicle is difficult to find the characteristics of motion during the operation on the track because these happen to independence or duplication motion caused by vehicle, wheel/rail and track irregularity etc. This paper presents the result of ramp test to show the bounce, roll, pitch and yaw mode frequency of the railway vehicle.

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단일링크 유연매니퓰레이터의 센서리스 진동제어 (Sensorless Vibration Control of a Single-Link Flexible Manipulator)

  • 한상수;신호철;서용칠;김승호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.233-236
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    • 2004
  • In this paper, a new sensorless vibration control scheme is proposed for a flexible manipulator system. A robust sliding mode controller incorporating with a ‘reaction moment observer’ used for the estimation of the reaction moment reciprocally acting on flexible arm and hub inertia is introduced to achieve desired control target. The rigid body dynamics of the single-link flexible manipulator is simply considered in the design of the sliding mode controller. Then, the reaction moment is estimated by the proposed reaction moment observer to suppress the residual vibration of the flexible arm. The performance of the proposed control scheme is verified by computer simulation and experiment.

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운동방정식에 의한 픽업 액추에이터 모드 분석 (A Mathematical Approach for Analysis of Modes in Pickup Actuators)

  • 이경택
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
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    • pp.73-78
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    • 2013
  • In this paper, the vibration for a pickup actuator is described by mathematically analyzing its suspension configuration and motion, confined to lateral and torsional directions of suspensions. In order to prove the accuracy of this result, it is compared to a finite element analysis. Also it is shown that modal frequencies can be modified by changing design parameters in mathematical motion expressions.

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