• Title, Summary, Keyword: Cantilever

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A Study on the Design of a Double Cantilever Structure Friction Tester for Precision Friction Measurement (정밀 마찰측정을 위한 이중 캔틸레버 구조 마찰시험기의 설계에 관한 연구)

  • Kang, Won-Bin;Kim, Hyun-Joon
    • Tribology and Lubricants
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    • v.34 no.4
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    • pp.125-131
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    • 2018
  • A precision tribometer consisting of a cantilever was designed to measure frictional forces in the micro-Newton range. As frictional forces are measured based on the bending of the cantilever, vibration of the cantilever is the most significant factor affecting the quality of the friction measurement. Therefore, improved design of the tribometer with double cantilevers and a connecting plate that united the two cantilevers mechanically was suggested. For the verification of the modified design of the tribometer, numerical analysis and experiments were conducted. Examination using the finite element method revealed that the tribometer with a double cantilever and a connecting plate exhibited faster damping characteristics than the tribometer with a single cantilever. In the experiment, effectiveness of the double cantilever and connecting plate for vibration reduction was also confirmed. Vibration of the tribometer with double cantilever decreased eight times faster than that of the tribometer with a single cantilever. The faster damping of the double cantilever design is attributed to the mechanical interaction at the contacting surfaces between the cantilever and the connecting plate. Tribotesting using the tribometer with a single cantilever resulted in random fluctuation of frictional forces due to the stick-slip behavior. However, using the tribometer with a double cantilever and connecting plate for the tribotest gave relatively uniform and steady measurement of frictional forces. Increased stiffness owing to using a double cantilever and mechanical damping of the connecting plate were responsible for the stable friction signal.

A THREE DIMENSIONAL FINITE ELEMENT STRESS ANALYSIS OF OSSEOINTEGRATED PROSTHESIS ACCORDING TO THE LOCATION AND LENGTH OF CANTILEVER (골유착성 임플랜트 보철물의 캔틸레버 위치와 길이변화에 따른 삼차원 유한요소법적 응력분석)

  • Jang, Bok-Sook;Kim, Chang-Whe;Kim, Yung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.3
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    • pp.501-532
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    • 1996
  • This study investigated the effects of cantilever length, location and load condition on stress distribution developed in the implants, prostheses and supporting tissues. The osseointegrated prostheses with two 10mm Branemark implants at 2nd premolar and 1st molar sites with cantilever extensions at 1st premolar, 2nd and 3rd molar sites were constructed. Under 100N, 200N of vertical and $45^{\circ}$ oblique loads at the cantilever pontics, stress distribution patterns and displacement were analyzed with three dimensional finite element method. The results were as follows : 1. The stress was concentrated at the joint of the cantilever pontic and implant superstructure, the neck of implant and the ridge crest near the cantilever But there was little load transfer to the lower supporting tissues of implants. 2. The implant near the cantilever was displaced inferiorly while the implant far from the cantilever was displaced superiorly. In horizontal direction the implants were displaced to the direction where the loads were applied, except the apexes of the implants. 3. In case of anterior cantilever, the stress and displacement were higher than the prosthesis connected with natural tooth. 4. The stress developed in the posterior cantilevered type was higher than in the anterior cantilevered type. The greastest stress was concentrated at the ridge crest near the posterior cantilever. 5. The longer the cantilever, the more the stress was developed and was concentrated at the joint of the cantilever pontic and implant superstructure. 6. Under oblique load, the stress was concentrated at the necks of implants and the ridge crests, but decreased at the joint of the cantilever pontic and implant superstructure than under vertical load.

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Development of Measurement System for Quantitative Measurement of Cantilever in Atomic Force Microscopy (원자간격 현미경의 캔틸레버의 정량적 특성평가를 위한 계측 시스템 개발)

  • Kweon, Hyun-Kyu;Nam, Ki-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.2
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    • pp.22-27
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    • 2007
  • In this study, the two methods of stiffness measurement(Spring constant) of cantilever were proposed for quantitative measurement in Atomic Force Microscopy(AFM). As the 1st method for the measurement of stiffness, the probe method, which is used in the measurement of the semiconductor mechanical and electrical properties, was applied to the measurement of the cantilever. Experiments by the probe method were performed finding the resistance value of cantilever. As the results, the resistance was measured differently along with the dimension and the thickness of cantilever that determined the stiffness(spring constant) of the lever. As the 2nd method, the vibration characteristics(Dunkerley expression) is used to obtain the stiffness of the complex structure which is combined by AFM cantilever and the standard cantilever. We measured the resonant frequency from the complex structure using the micro stages and stereo microscope. As the results, we confirmed that the vibration characteristics(Dunkerley expression) is effected the micro complex structure of AFM cantilever.

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Dynamic Behavior of Rotating Cantilever Pipe Conveying Fluid with Moving mass (이동질량을 가진 유체유동 회전 외팔 파이프의 동특성)

  • Son, In-Soo;Yoon, Han-Ik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.308-311
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    • 2005
  • In this paper, we studied about the effects of the rotating cantilever pipe conveying fluid with a moving mass. The influences of a rotating angular velocity, the velocity of fluid flow and moving mass on the dynamic behavior of a cantilever pipe have been studied by the numerical method. The equation of motion is derived by using the Lagrange's equation. The cantilever pipe is modeled by the Euler-Bemoulli hew theory. When the velocity of a moving mass is constant, the lateral tip-displacement of a cantilever pipe is proportional to the moving mass and the angular velocity. In the steady state, the lateral tip-displacement of a cantilever pipe is more sensitive to the velocity of fluid than the angular velocity, and the axial deflection of a cantilever, pipe is more sensitive to the effect of a angular velocity.

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Study on the Analysis of Anisotropic Laminated Cantilever Thin Plates and Anisotropic Laminated Cantilever Thick Plates (비등방성 적층 캔틸레버 박판 및 후판의 해석연구)

  • Park, Won-Tae
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.1 no.4
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    • pp.1-5
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    • 2010
  • In this study, it is presented analysis results of bending problems in the anisotropic cantilever thick plates and the anisotropic laminated cantilever thin plates bending problems. Finite element method in this analysis was used. Both Kirchoff's assumptions and Mindlin assumptions are used as the basic governing equations of bending problems in the anisotropic laminated plates. The analysis results are compared between the anisotropic laminated cantilever thick plates and the anisotropic laminated cantilever thin plates for the variations of thickness-width ratios.

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Natural Frequency of Rotating Cantilever Pipe Conveying Fluid with Tip Mass (끝단질량을 가진 유체유동 회전 외팔 파이프의 고유진동수 해석)

  • Yoon, Han-Ik;Son, In-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.10
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    • pp.150-157
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    • 2005
  • The vibration system in this study is consisted of a rotating cantilever pipe conveying fluid and a tip mass. The equation of motion is derived by using the Lagrange's equation. The influences of the rotating angular velocity and the velocity of fluid flow on the natural frequencies of a cantilever pipe have been studied by the numerical method. The effects of a tip mass on the natural frequencies of a rotating cantilever pipe are also studied. The influences of a tip mass, the velocity of fluid, the angular velocity of a cantilever pipe and the coupling of these factors on the natural frequency of a cantilever pipe are analytically clarified. The natural frequencies of a cantilever pipe conveying fluid are proportional to the angular velocity of the pipe in both axial direction and lateral direction.

A Study on the Changes of Cantilever Chair (캔틸레버(Cantilever) 의자의 변천에 관한 연구)

  • Kang, Hyun-Dae
    • Journal of the Korea Furniture Society
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    • v.27 no.4
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    • pp.263-270
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    • 2016
  • Range of cantilever construction that specializes in bridge and building has been extended, the process that affects the cantilever chair is the overall flow. 1926, appeared by Mart stam, cantilever chair has achieved a great development in a short period of time that has not been 100 years up to now. On the basis of age and the feature "Initial stage" - "Growth & Apotheosis stage" - "Application stage", was divided into the total three stages. And an understanding of the evolution of the cantilever chair that occupies an important part in the history of the chair design, is intended to consider the direction to go in the future.

The Study of Characteristics Evaluation for Bimorph PZT Cantilever and its Application (바이몰프 PZT 캔틸레버 특성평가 및 응용연구)

  • 김석삼;채영훈;권현규
    • Tribology and Lubricants
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    • v.19 no.3
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    • pp.133-138
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    • 2003
  • The characteristics for bimorph PZT cantilever of laboratory-fabricated have been evaluated experimentally. The deflections of cantilever with PZT are result from a capillary force between a water drop and a tip of cantilever. The output voltage due to deflect cantilever are depend on the tip shape and thickness of cantilever. We applied a bimorph PZT cantilever to oil thickness measurement. This reasonable concept is that the output voltage be caused by different defected characteristics between oil and surface. Experimental results demonstrated that the high measurement accuracy of the oil film thickness is obtained from the probe.

Dynamic Characteristics of Cantilever Pipe Conveying Fluid with the Moving Masses (이동질량을 가진 유체유동 외팔 파이프극 동특성)

  • 윤한익;손인수
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.7
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    • pp.550-556
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    • 2002
  • The vibrational system of this study is consisted of a cantilever pipe conveying fluid. the moving mass upon it and an attacked tip mass. The equation of motion is derived by using Lagrange equation. The influences of the velocity and the inertia force of the moving mass and the velocities of fluid flow in the pipe haute been studied on the dynamic behavior of a cantilever pipe by numerical method. As the velocity of the moving mass increases, the deflection of cantilever pipe conveying fluid is decreased. Increasing of the velocity of fluid flow make the amplitude of cantilever pipe conveying fluid decrease. The deflection of the cantilever pipe conveying fluid is increased by moving masses. After the moving mass passed upon the cantilever pipe, the amplitude of pipe is influenced due to the deflection of pipe tilth the effect of moving mass and gravity.

Piezoelectric PZT Cantilever Array Integrated with Piezoresistor for High Speed Operation and Calibration of Atomic Force Microscopy

  • Nam, Hyo-Jin;Kim, Young-Sik;Cho, Seong-Moon;Lee, Caroline-Sunyong;Bu, Jong-Uk;Hong, Jae-Wan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.2 no.4
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    • pp.246-252
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    • 2002
  • Two kinds of PZT cantilevers integrated with a piezoresistor have been newly designed, fabricated, and characterized for high speed AFM. In first cantilever, a piezoresistor is used to sense atomic force acting on tip, while in second cantilever, a piezoresistor is integrated to calibrate hysteresis and creep phenomena of the PZT cantilever. The fabricated PZT cantilevers provide high tip displacement of $0.55\mu\textrm{m}/V$ and high resonant frequency of 73 KHz. A new cantilever structure has been designed to prevent electrical coupling between sensor and PZT actuator and the proposed cantilever shows 5 times lower coupling voltage than that of the previous cantilever. The fabricated PZT cantilever shows a crisp scanned image at 1mm/sec, while the conventional piezo-tube scanner shows blurred image even at $180\mu\textrm{m}/sec$. The non-linear properties of the PZT actuator are also well calibrated using the piezoresistive sensor for calibration.