• 제목/요약/키워드: Torsional Vibration Analysis

검색결과 303건 처리시간 0.023초

선반 기어박스의 기어열 - 축계 진동 해석 및 저감에 관한 연구 (Vibration Analysis and Reduction of the Geared Transmission System in a Lathe Gear Box)

  • 최영휴;박선균;배병태;정택수;김청수
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
    • /
    • pp.435-440
    • /
    • 2001
  • In this study, torsional and lateral vibrations of a gear box transmission system were analyzed theoretically using some mathematical models and examined to determine the causes of its excessive vibrations. As the results, it was found there exist possibility of resonance between gear mesh frequencies and lateral vibration mode of the transmission shaft during the third shifting mode operation. In order to avoid this resonance, we proposed changing the arrangement of gears on the transmission shaft. The measured vibration levels of the improved gear box were dramatically reduced. These results may be helpful to design a machine tool gear box with low noise and vibration.

  • PDF

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

  • 이경택
    • 한국소음진동공학회논문집
    • /
    • 제23권6호
    • /
    • pp.537-545
    • /
    • 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.

선반 기어박스의 진동.소음 분석과 저감에 관한 연구 (A Study on Vibration and Noise Reduction of a Lathe Gear Box)

  • 박선균;최영휴;배병태;정택수;김청수
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2001년도 춘계학술대회논문집
    • /
    • pp.552-558
    • /
    • 2001
  • When operating lathe gear box which is equipped with geared transmission, it sometimes generates loud noise and excessive vibrations. In order to identify their causes, in this study, torsional and lateral vibration characteristics including critical speeds of the gear transmission system are firstly analyzed using lumped parameter models. Natural frequencies and mode shapes of the gear box structure are also analyzed by using the modal test. Furthermore, measured vibration and noise signals during operations are analyzed and compared with theoretical analysis results. After all, it is concluded that the primary cause of the excessive noise and vibrations is the resonance between gear meshing frequency including its side bands, the frequencies of shaft bending and torsional vibrations, and the natural frequencies of the gear box structure. Consequently the noise and vibration levels are greatly reduced by avoiding resonance between the natural frequencies and gear meshing frequencies through the rearrangement of the gears on the transmission shaft without any gear ratio change.

  • PDF

박벽 C형 복합재료 보의 휨-비틀림 진동 해석 (Flexural-torsional Vibration Analysis of Thin-walled C-Section Composite Beams)

  • 김영빈;이재홍
    • 한국강구조학회 논문집
    • /
    • 제14권1호
    • /
    • pp.31-40
    • /
    • 2002
  • 적층된 박벽 복합재료 보의 자유 진동에 관한 연구를 수행하였다. 박벽 C형강 복합재료의 동적 거동에 적용 가능한 일반적인 해석 모델을 개발하였다. 이 모델은 classical lamination theory를 기초로 두고 있으며, 임의의 적층 상태의 구성 즉, 대칭뿐만 아니라 비대칭의 적층 상태, 그리고 다양한 경계조건에 따른 휨과 비틀림 형상의 연계(coupling)을 설명하였다. 변위를 기반으로 한 일차원 유한 요소 모델은 박벽 복합재료 보의 고유 진동수와 그에 대응하는 진동 모드를 예측하기 위해 개발되었다. 운동방정식은 Hamiton의 원리로부터 유도되었으며, 수치적인 결과는 박벽 복합재 보에서 복합재료의 진동수와 모드 형상에 대해 적층각, 계수비, 그리고 경계조건의 영향을 얻을 수 있었다.

점성댐퍼를 갖는 엔진 축계의 비선형 비틀림강제진동 (Nonlinear Forced Torsional Vibration for the Engine Shafting System With Viscous Damper)

  • 박용남;송성옥;김의간;전효중
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제20권4호
    • /
    • pp.50-58
    • /
    • 1996
  • The torsional vibration of the propulsion shafting system equipped with viscous damper is investigated. The equivalent system is modeled by a two mass softening system with Duffing's oscillator and the vibratory motion is described by non-linear differential equations of second order. The damper casing is fixed at the front-end of crankshaft and the damper's inertia ring floats in viscous silicon fluid inside of the camper casing. The excitation frenquency is proportional to the rotational speed of engine. The steady state response of the equivalent system is analyzed by the computer and for this analyzing, the harmonic balance method is adopted as a non-linear vibration analysis technique. Frequency response curves are obtained for 1st order resonance only. Jump phenomena are explained. The discriminant for the solutions of the steady state response is derived. Both theoretical and measured results of the propulsion shafting system are compared with and evaluated. As a result of comparisions with both data, it was confirmed that Duffing's oscillator can be used in the modeling of the propulsion shafting system attached with viscous damper with non-linear stiffness.

  • PDF

점성댐퍼를 갖는 엔진 축계의 비선형 비틀림강제진동 (Nonlinear Forced Torsional Vibration for the Engine Shafting System With Viscous Damper)

  • 박용남;송성옥;김의간;전효중
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제20권4호
    • /
    • pp.372-372
    • /
    • 1996
  • The torsional vibration of the propulsion shafting system equipped with viscous damper is investigated. The equivalent system is modeled by a two mass softening system with Duffing's oscillator and the vibratory motion is described by non-linear differential equations of second order. The damper casing is fixed at the front-end of crankshaft and the damper's inertia ring floats in viscous silicon fluid inside of the camper casing. The excitation frenquency is proportional to the rotational speed of engine. The steady state response of the equivalent system is analyzed by the computer and for this analyzing, the harmonic balance method is adopted as a non-linear vibration analysis technique. Frequency response curves are obtained for 1st order resonance only. Jump phenomena are explained. The discriminant for the solutions of the steady state response is derived. Both theoretical and measured results of the propulsion shafting system are compared with and evaluated. As a result of comparisions with both data, it was confirmed that Duffing's oscillator can be used in the modeling of the propulsion shafting system attached with viscous damper with non-linear stiffness.

NONLINEAR ANALYSIS OF SELF-EXCITED VIBRATION IN WHEELED TRACTOR VEHICLE'S DRIVELINE

  • Li, X.H.;Zhang, J.W.;Zeng, C.C.
    • International Journal of Automotive Technology
    • /
    • 제7권5호
    • /
    • pp.535-545
    • /
    • 2006
  • A nonlinear analysis of torsional self-excited vibration in the driveline system for wheeled towing tractors was presented, with a 2-DOF mathematical model. The vibration system was described as a second-order ordinary differential equation. An analytical approach was proposed to the solution of the second-order ODE. The mathematical neighborhood concept was used to construct the interior boundary and the exterior boundary. The ODE was proved to have a limit cycle by using $Poincar\'{e}-Bendixson$ Annulus Theorem when two inequalities were satisfied. Because the two inequalities are easily satisfied, the self-excited vibration is inevitable and even the initial slip rate is little. However, the amplitude will be almost zero when the third inequality is satisfied. Only in a few working modes of the towing tractor the third inequality is not satisfied. It is shown by experiments that the torsional self-excited vibration in the driveline of the vehicle is obvious.

비정형 구조물의 평면 회전축과 코어의 이동에 따른 지진응답분석 (Analysis of Seismic Response by the Movement of the Plane Rotation Axis and the Core of Atypical Structures)

  • 이다혜;김현수;강주원
    • 한국공간구조학회논문집
    • /
    • 제22권1호
    • /
    • pp.33-40
    • /
    • 2022
  • When the center of stiffness and the center of mass of the structure differ under the seismic load, torsion is caused by eccentricity. In this study, an analysis model was modeled in which the positions of the core and the plane rotation axis of a 60-story torsional atypical structure with a plane rotation angle of 1 degree per floor were different. The structural behavior of the analysis model was analyzed, and the earthquake response behavior of the structure was analyzed based on the time history analysis results. As a result, as the eccentricity of the structure increased, the eccentricity response was amplified in the high-rise part, and the bending and torsional behavior responses were complex in the low-order vibration mode. As a result of the analysis, the maximum displacement and story drift ratio increased due to the torsional behavior. The maximum story shear force and the story absolute maximum acceleration showed similarities for each analysis model according to the shape of the vibration mode of the analysis model.

자동차 시트 및 마네킹 시스템의 강제 진동 (Forced Vibration of Car Seat and mannequin System)

  • 김성걸
    • 한국정밀공학회지
    • /
    • 제17권9호
    • /
    • pp.122-132
    • /
    • 2000
  • A simplified modeling approach of forced vibration for occupied car seats was demonstrated by using a mathematical model presented in 'Free Vibration of Car seat and Mannequin System' nonlinear and linear equations of motions were rederived for forced vibration and the transfer function was used to calculate the frequency response function. The experimental apparatus were set up and hydraulic shaker was used to obtain the system responses. Through the tests mannequin's head had a lot of problems and the responses with a head and without a head were measured. To explore the effects of linear dampings and friction moments at the joints linear analyses were performed. New sets of linear spring and damping coefficients and torsional dampings at the joints were calculated through parameter study to match up with experimental results. Good agreement between experimental and simulation frequency response estimates were obtained both in terms of locations of resonances and system deflection shapes at resonance indicating that this is a feasible method of modeling seated occupants.

  • PDF

밀링가공에서 공구마모와 스핀들의 비틀림 진동과의 상관관계에 관한 연구 (Research on the Effect of Cutter Wear on the Torsional Vibration of Spindle in Milling)

  • 김석관
    • 한국정밀공학회지
    • /
    • 제16권9호
    • /
    • pp.62-67
    • /
    • 1999
  • In milling, cutting tool ins directly attached to spindle and this tells that spindle can provide very useful information on the cutting tool condition such as wear or breakage. Since spindle is rotating at a high speed, measuring spindle velocity using a noncontacting measurement system gives the best information which can be obtained. Due to the force applied to spindle through cutting tool, velocity of spindle changes. And any change in cutting tool condition affects cutting force and consequently spindle vibration. With the intent of continuously monitoring cutting tool condition in intermittent machining operations in a benign manner, a noncontacting velocity measurement system using a laser Doppler velocimeter was assembled to measure spindle torsional vibration. Spindle vibration was measured and analysis of it in the frequency domain yielded a measure which corresponded to amount of cutting tool wear in milling.

  • PDF