• 제목/요약/키워드: Vibrational Characteristics

검색결과 325건 처리시간 0.038초

선형동흡진기의 매개변수가 감쇠진동계의 진동특성에 미치는 영향 (Effects of parameters of a linear dynamic vibration absorber on the vibrational characteristics of damped vibrational systems)

  • 윤장상;이양우;송창섭
    • 한국정밀공학회지
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    • 제6권4호
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    • pp.136-144
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    • 1989
  • This paper presents the vibrational characteristics of linear damped vibrational systems with a linear dynamic absorber. The amplitude ratios of main vibrational system are derived from the equation of motion for the system, and optimal natural frequency ratio and damping ratio of dynamic absorber are obtained by computer simu- lation, which minimize the amplitude ratio of main vibrational system for the whole range of the frequency ratio. And, the effects of the parameters on the amplitude ratios are investigated. As the results, the effect of the natural frequency ratio on the amplitude ratio of main vibrational system is more important than that of the damping ratio of dynamic absorber as damping ratio of main vibrational system becomes larger. For the case of large damping ration of main vibrational system becomes larger. For the case of large damping ratio of main vibration system, the amplitude ratios are not decreased dramationally in spite of inoreasing mass ratio.

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유체가 흐르는 가스파이프의 진동 특성 (Vibrational Characteristics of the Gas Pipelines Conveying Flow)

  • 김경태;이성수;이성우
    • 한국생산제조학회지
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    • 제21권2호
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    • pp.337-343
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    • 2012
  • This work investigates the vibrational characteristics of the underground gas pipelines. Experiments were conducted to analyze the effects of various parameters on the vibrational characteristics from the emergency detection point of view. Influences of the various types of impact exerted on the pipe, height of free fall and measuring locations were analyzed. Especially, the difference between the vibrational signal generated by the direct impact on the pipe and the ambient noise was successfully identified. To validate the experimental observation, computer simulation was also performed with constant properties(elasticity, fluid velocity and internal pressure) which are directly conjectured from the accompanying experiment with a real pipe system.

CW $CO_{2}$ 레이저의 온도 특성에 관한 해석 (The theoretical analysis of characteristics for temperatures in cw $CO_{2}$ laser)

  • 강동헌;박득일;이주희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.465-468
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    • 1988
  • The output power is dependent of the vibrational level temperatures and wall temperature of the discharge tube in cw $CO_{2}$ lasers. The method postulates the introduction of a vibrational temperatures Ti for each vibrational mode. The vibrational and wall temperature are dertermined by the equations of the vibrational energy balance and thermal conductivity.

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설계변수 변화에 대한 KTX 가선계의 응답 특성 (Vibrational Characteristics of KTX Catenary System for Changing Design Parameters)

  • 박성훈;김정수;조용현;최강윤
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2001년도 춘계학술대회 논문집
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    • pp.265-272
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    • 2001
  • Dynamic characteristics of catenary system for KTX Korean high-speed trains are investigated. A simulation program based on the finite element models of the catenary is developed. The influences of the various design parameters on the vibrational responses of the catenary are determined. The main design parameters include tension on the contact and messenger wires and the stiffness of the droppers connecting the two wires. The vibrational responses are primarily determined by the reflections of the propagating wave, and the dropper stiffness is found to be the dominant factor that influences overall dynamic characteristics of the catenary.

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지지방식의 차이에 따른 나노 임프린팅 스테이지의 진동 특성 비교 (The vibrational characteristics of nano-imprinting stages with respect to supporter types)

  • 이성훈;박성빈;이강욱;정재일;임홍재
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.948-954
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    • 2008
  • In this study, vibrational characteristics of two nano-imprinting stages is analyzed and compared with respect to the methodology to support the upper-plate of the stage. The first type of the stage has three supporters at each corners of the stage and one thrust bearing at the center of the stage. The other type of the stage has four supporter in each corner of the stage without a thrust bearing. The FEM software with flexible modeling is used for the normal mode analysis. The result depicts the difference of vibrational characteristics caused by the difference of support methods. The design criteria for the precision nano-imprinting stage is also discussed.

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주변암반과의 상호거동 해석을 통한 지하구조물의 진동특성에 관한 연구 (A Study of Vibrational Characteristics of Underground Structures through Rock-Structure Interaction Analysis)

  • 김문겸;이재영;김용규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.229-234
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    • 1997
  • The dynamic behavior of underground structures is complex due to the effects of vibrational characteristics of the structure and the rock. In this study, dynamic displacement responses at the structure surface by the elastic stress waves are considered as the vibrational characteristics, and evaluated by the form of the frequency spectrum. The variation of the vibrational characteristic is simulated by numerical analysis at the case of the structure has internal defections. The results reveals the possibility of the experimental detection of void existence and size. Furthermore, the verification of the dynamic response can be used for rating the stability of a tunnel.

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Characteristics in Molecular Vibrational Frequency Patterns between Agonists and Antagonists of Histamine Receptors

  • Oh, S. June
    • Genomics & Informatics
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    • 제10권2호
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    • pp.128-132
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    • 2012
  • To learn the differences between the structure-activity relationship and molecular vibration-activity relationship in the ligand-receptor interaction of the histamine receptor, 47 ligands of the histamine receptor were analyzed by structural similarity and molecular vibrational frequency patterns. The radial tree that was produced by clustering analysis of molecular vibrational frequency patterns shows its potential for the functional classification of histamine receptor ligands.

자동차 배기계의 진동특성의 평가 및 개선에 관한 연구 (Evaluation and improvement of the vibrational characteristics in the automotive exhaust system)

  • 박호;전의식;오재응;임동규
    • 오토저널
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    • 제12권4호
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    • pp.47-55
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    • 1990
  • This study is the first step for the grasp of transfer path to the vibration generated from the automotive engine and consideration of counterplan for optimal design and low vibration, low noise of the exhaust system. In this study, by applying the theory of modal analysis and experiment, vibrational reduction effect is evaluated according to the attachment of flexible coupling to the exhaust system. And data for the design is suggested to improve the characteristics of vibration. The vibration isolation and damping characteristics are improved due to the attachment of flexible coupling to the exhaust system. As a result, it is identified that flexible coupling which has good flexibility is more effective for the improvement of vibrational characteristics. By the estimation of modeshape of vibration, the location of optimal damping hanger is determined in the viewpoint of vibration isolation. Also it is confirmed that the characteristics of vibration is improved due to the attachment of damping hanger.

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직교형 2차원 진동절삭기의 기구학적 해석 및 진동 특성 고찰 (Kinematical Analysis and Vibrational Characteristics of Orthogonal 2-dimensional Vibration Assisted Cutting Device)

  • 노병국;김기대
    • 한국소음진동공학회논문집
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    • 제22권9호
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    • pp.903-909
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    • 2012
  • In elliptical vibration cutting(EVC) where the cutting tool traces a micro-scale 2-dimensional elliptical trajectory, the kinematical and vibrational characteristics of the EVC device greatly affect cutting performance. In this study, kinematical and vibrational characteristics of an EVC device constructed with two orthogonally-arranged stacked piezoelectric actuators were investigated both analytically and experimentally. The step voltage was applied to the orthogonal EVC device and the associated displacements of the cutting tool were measured to assess kinematical characteristics of the orthogonal EVC device. To investigate the vibrational characteristic of the orthogonal EVC, sinusoidal voltage was applied to the EVC device and the resulting displacements were measured. It was found from experiments that coupling of displacements in the thrust and cutting directions and the tilt of the major axis of the elliptical trajectory exists. In addition, as the excitation frequency is in vicinity of resonant frequencies the distortion in the shape of the elliptical trajectory becomes greater and change in the rotation direction occurs. To correct the shape distortion of the elliptical trajectory, the shape correcting procedure developed for the parallel EVC device was applied for the orthogonal EVC device and it was shown that the shape correcting method successfully corrects distortion.

질량감도 해석에 의한 2차원 연속계의 진동특성에 관한 연구 (A Study on The Identification of Characteristics For The 2 Dimensional Continuous Vibration System By Mass Sensitivity Analysis)

  • 이정윤;박호;오재응
    • 대한기계학회논문집
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    • 제14권2호
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    • pp.339-348
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    • 1990
  • Techniques which are able to predict and control dynamic characteristics, not affecting the vibrational characteristics on the modification of structural design, are being studied. As one of these techniques, experimental modal analysis is widely applied by many researchers. In this study, modal analysis is performed using transfer matrix method by a macro computer. The developed program would estimate the structural modal parameters precisely, and the validity of this program is certified by comparing with the experimental results of .GAMMA A. structure. Estimated modal parameters(natural frequency, vibrational mode, equivalent mass, etc.) are in accord with the experimental results. Also, the optimal location of the additive mass is determined by the evaluation of the vibrational mode and the equivalent mass. The relation between the additive mass and the equivalent mass is specified, and we come to know that the ratio of equivalent mass to additive mass alter linearly within the range of 20%.