• 제목/요약/키워드: Non-contact method

검색결과 837건 처리시간 0.044초

Z-map으로 표현된 수직 벽면을 가진 금형에서의 접촉처리법과 클로버형 컵 디프드로잉 공정의 해석에의 응용 (Contact treatment algorithm of z-map model with vertical walls and its application to the deep drawing of a clover shaped cup)

  • 서의권;박정환;심현보
    • 한국생산제조학회지
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    • 제7권5호
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    • pp.38-45
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    • 1998
  • The Z-map model which is quite similar to the non-parametric patch is widely used to describe the shape of a surface because of its simplicity. Despite the inherent advantage of z-map model. it has drawbacks that there exists difficulty in expressing the vertical walls and its related contact treatment method. In the region of vertical walls, there is a convergence problem in searching the contact point. In this study a contact point finding scheme is presented, based on the z value of the z-map model on the sheet normal direction. To show the utility of this scheme a compared with the experimental results. The effects of the Z-map grid distances and the interpolations of the inside Z-map value are also discussed.

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비접촉 충전을 위한 ZVS 다중공진 포워드 컨버터의 설계 (A Design of ZVS Multi-Resonant Forward Converter for Non-contact Charging)

  • 김영길;나희수;김진우;이성백
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.1300-1302
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    • 2000
  • In the charge system, a contact type-convenient-charging method is insufficient because of the contact failure around moist environment and troublesome question to put in and pull out. For the solution of this problem, an electromagnetically coupled non-contact charger for the rechargeable cell is proposed using ZVS multi-resonant forward converter. In this paper magnetizing inductance, leakage inductance and coupling coefficient, k are observed. By using the obserbed value, the proposed circuit is simulated by the PSPICE and implemented and the peak voltage of switch and output power are measured.

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유연도 영향계수법을 이용한 접촉 결합 부의 모델링 (Finite Element Modeling of Contact Joints by Flexibility Influence Coefficient)

  • 조성욱;오제택
    • 한국정밀공학회지
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    • 제23권6호
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    • pp.128-135
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    • 2006
  • Rational dynamic modeling and analysis method f3r complex structures are studied with special attention to slide way joints. For modeling of slide way joints, a general modeling technique is used by using the influence coefficients method which is applied to the conversion of detailed finite element model to the equivalent reduced joint model. The theoretical part of this method is illustrated and the method is applied to the structure with slide way joint. In this method, the non-linearity of the contact surfaces is considered within a proper range and the boundary effect of the joint model could be eliminated. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam and slide way joints of the vertical type lathe. The method can also be used to other kinds of joint modeling. The results of these analysis were compared with those of Yoshimura models and rigid joint models, which demonstrated the practical applicability of the proposed method.

병렬도체에서 선재의 배열형상에 따른 비접촉식 전류분류 측정 (Current sharing measurement using non-contact method for parallel HTS tapes conductor according to tape array geometry)

  • 변상범;박명진;최석진;박상호;이승욱;김우석;이지광;최경달
    • 한국초전도ㆍ저온공학회논문지
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    • 제10권1호
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    • pp.32-36
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    • 2008
  • An HTS conductor with parallel HTS tapes is essential for a large power HTS device to flow a large current. One of the most important factor for this conductor is a current distribution. Non-uniform current distribution in parallel tapes makes the critical current of the conductor low and the AC losses high. In this paper we proposed a non-contact method which measured each current in parallel tapes by using an array of Hall sensors. A matrix can be derived from this array for calibration. The current distributions of 4 and 6 parallel tapes were measured.

비접촉 SH-EMAT을 이용한 TIG용접부 건전성 평가 (Evaluation of the Integrity of TIG Welding Using Non-Contact SH-EMAT)

  • 박태성;박영환;박익근
    • 한국생산제조학회지
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    • 제25권1호
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    • pp.48-53
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    • 2016
  • An EMAT can be used to reliably detect defects as it serves as a non-contact transducer with the ability to transmit ultrasonic waves into specimens without couplant. Moreover, an EMAT can easily generate desired waves by altering the design of the coil and magnet. This study proposes an SH-EMAT to evaluate the integrity of the TIG welding part. A stainless steel was welded using the TIG welding method. The welding current was varied to create artificial defects. Both the PA-UT and the RT were applied to verify the defect size. The experimental results generated by using the EMAT were compared with those methods. The amplitude was observed to decrease with an increase in the defect size. These results confirmed that the presence of defects can be reliably detected by attenuation of signal amplitude. The results demonstrated that the proposed method is suitable for evaluating the integrity of TIG welding.

레이저 간섭계를 이용한 곡률반경 측정에 관한 연구 (A Study on Curvature Radius Measurement Using Laser Interferometer)

  • 이지용;김민주;이승수;전언찬
    • 한국공작기계학회논문집
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    • 제13권6호
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    • pp.34-40
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    • 2004
  • This paper presents studies on curvature radius measurement using the laser interferometer. It is a general practice to measure to $10^{-10}$m in length with the recent improvement and innovations in measurement technology and the processor used. The measurement methods can generally be categorized as these two: the contactual method and non-contactual method; and in this study, we will find ways to lower the cost for a CMM, or a coordinate measurement machine, and try to find an alternative. Furthermore, we will discuss some of the ways to improve the non-contactual measurement methods-optical interferometer method and the optical triangulation method. We will measure an object using a laser distance measuring device and Set the Point-contact result with the ball-bearing type and line-contact result with the bearing type, to decide on which probe type will be used.

홀로그래픽 간섭법을 이용한 압력용기의 내부결함 측정법 (The measruement method for internal defect of pressure vessels by using holographic interferometry)

  • 문상준;강영준;최장섭
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 춘계학술대회 논문집
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    • pp.377-382
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    • 1995
  • Conventional measurement methods using ultrasonic wave or x-ray, eddy current for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the method of contact with objects to be inspected. With this reason these methods have been taken relatively much time and the inspected area is limited by the location of probe or film. But holographic interferometry which is a non-contact optical measurement method using a coherent light source has an advantage that the quantitative measurement can be performed at a time. In this paper a new method using holographic interferometry and image processing for detecting internal flaws of pressure vessels is presented.

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Metal Fastening 공법을 위한 Reverse Screw의 견인력 특성에 관한 연구 (A Study on the Pulling Force Characteristic of the Reverse Screw for the Metal Fastening Method)

  • 김태형;이성욱;한근조
    • 한국기계가공학회지
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    • 제9권1호
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    • pp.93-98
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    • 2010
  • The metal fastening method is the new technology to repair cracks in the casting material using specially designed reverse screws. In this study, we conduct the finite element analysis to analyze the pulling force characteristic of a reverse screw, the core component of the metal fastening method, with respect to the change of the applying torque, frictional coefficient and front screw angle. The simplified analysis model with single screw pitch is proposed for convergency of the non-linear contact analysis. As a results, the pulling force of a reverse screw increase in proportion to the applying torque but exponentially decrease according to frictional coefficient. And also we can find the optimum front screw angle with the largest pulling force is $20^{\circ}$.

Finite element modeling of contact between an elastic layer and two elastic quarter planes

  • Yaylaci, Murat;Avcar, Mehmet
    • Computers and Concrete
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    • 제26권2호
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    • pp.107-114
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    • 2020
  • In this study, a two dimensional model of receding contact problem has been analyzed using finite element method (FEM) based software ANSYS and ABAQUS. For this aim finite element modeling of elastic layer and two homogeneous, isotropic and symmetrical elastic quarter planes pressed by means of a rigid circular punch has been presented. Mass forces and friction are neglected in the solution. Since the problem is examined for the plane state, the thickness along the z-axis direction is taken as a unit. In order to check the accuracy of the present models, the obtained results are compared with the available results of the open literature as well as the results of two software are compared using Root Mean Square Error (RMSE) and good agreements are found. Numerical analyses are performed considering different values of the external load, rigid circular radius, quarter planes span length and material properties. The contact lengths and contact stresses of these values are examined, and their results are presented. Consequently, it is concluded that the considered non-dimensional quantities have noteworthy influence on the contact lengths and contact stress distributions, additionally if FEM analysis is used correctly, it can be an efficient alternative method to the analytical solutions that need time.

Al6061 합금의 소성변형에 따른 음향비선형 특성의 완전 비접촉식 평가 (Fully Non-Contact Assessment of Acoustic Nonlinearity According to Plastic Deformation in Al6061 Alloy)

  • 이현;전청;김정석;장경영
    • 비파괴검사학회지
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    • 제32권4호
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    • pp.388-392
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    • 2012
  • 본 연구에서는 표면파의 음향비선형 특성 측정을 위해 선 배열 레이저 빔을 이용하여 협대역의 표면파를 발생시키고 레이저 TWM(Two-Wave Mixing) 방식으로 수신하는 완전 비접촉 측정 방법이 도입되었다. 이 기술은 알루미늄 합금의 소성변형과 음향비선형 특성과의 상관성을 조사하는데 적용되었다. 그 결과, 재료의 소성변형에 따라 음향 비선형성이 비례적으로 증가하는 것으로 나타났으며, 이는 접촉식 PZT 탐촉자 수신 방법으로 측정한 결과와 동일한 경향이다.