• 제목/요약/키워드: Trapezoidal Spline

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상계법을 이용한 스플라인 단조에 관한 연구 (Study for Forging of Spline with Upper Bound Method)

  • 조해용;최재찬;최종웅;민규식
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1995년도 추계학술대회논문집
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    • pp.37-47
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    • 1995
  • Forging of trapezoidal spline, serration and square spline with solid cylindrical billets and hollow one has been investigated by means of upper bound method. Kinematically admissible velocity fields for forging of splines have been proposed in this study. The half pitch of splines has been divided into deformation regons. The neutral surface is introduced into forging of splines with flat punch and, for each step, it is assumed as a circle with its radius rn upper bound solutions obtained obtained by proposed kinematically admissible velocity fields are useful to predict the loads for forging of splines.

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기어류 부품의 단조에 관한 상계해석 (Upper Bound Analysis on the Forging of Gear-Like Components)

  • Min, G.S.;Park, J.U.;Lee, H.C.
    • 한국정밀공학회지
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    • 제14권2호
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    • pp.102-112
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    • 1997
  • This paper describes the method that can construct kinematically admissible velocity fields for forging of gear-like components which have tooth shape around the cylinder. The kinematically admissible velo- city fields for the various gear-like components, involute spur gear, trapezoidal spline, square spline, ser- ration and trochoidal gear, were constructed by pilling up the velocity components according to the shape of tooth and billet. The billets, of hollow and solid, were Al 2218 and 2024. To verify the method, the analyses and experiments were carried out and compared with each other. For analyses, the half pitches of com- ponents were divided into several deformation regions based on their tooth profile. A neutral surface was used to represent the inner flow of material during forging. Its location varied with the energy optimazation and its contour varied with the number of teeth. In experiment, the contour of material filling up the tooth zone is hyperbolic curve caused by the frictional drag on the interface of die-wall/workpiece but, in the analysis, it is an arc which retains the same contour during all forging operation.

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중공 및 중실소재를 이용한 스플라인 단조에 관한 연구 (Study on the Forging of Splines with Hollow and Solid Billets)

  • 조해용;최종웅;민규식
    • 한국정밀공학회지
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    • 제13권1호
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    • pp.108-115
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    • 1996
  • Forging of trapezoidal spline, serration and square spline with solid cylindrical billets and hollow one has been investigated by means of upper bound method. Kinematically admissible velocity fields for forging of splines have been proposed in this study. The half pitch of spline has been divided into several deformation regions. The neutral surface is introduced into forging of splines with flat punch and, for each step, it is assumed as a circle with its radius $r_n$. Upper bound solutions obtained by proposed kinematically admissible velocity fields are useful to predict the loads for forging of splines.

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상계요소법에 의한 External Spline의 Near-Net 단조해석 (An Analysis of Near-Net Forging of External Spline by an Upper Bound Elemental Technique)

  • 양정호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.206-211
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    • 1996
  • Closed-die forging of external spine is analysed using an upper bound elemental technique. The kinematically admissible velocity field for three-dimensional deformation in forging of the external spine with trapezoidal teeth was obtained. The upper bound to the deforming load necessary and the the deformed configurations are predicted using integration of the formulation of energy expressions which were obtained from B(upset forging method) were considerd in the present analysis and the theoretical results compared with experimental ones Experiments were carried out on plasticine as model material at room temperature where talcum powder was used as a lubricant. The present investigation revealed that the analytical method B predicts a reducet forging load and improved configuration better than method A for the forged products.

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매립토공량 계산식에 관한 연구 (A Study on the Reclamation Earthwork Calculation Formula)

  • 이용희;문두열
    • 한국항만학회지
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    • 제15권1호
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    • pp.87-97
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    • 2001
  • The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to advanced the accuracy of earthwork calculation. Current method used for estimating the volume of pit excavation assumes that the ground profile between the grid points is linear(trapezoidal rule), or nonlinear(simpson's formulas). In this paper the spot height method, least square method, and chamber formulas, Chen and Lin method are compared with the volumes of the pits in these examples. As a result of this study, algorithm of chen and Lin me쇙 by spline method should provide a better accuracy than the spot height method, least square method, chamber formulas. The Chen and Lin formulas can be used for estimating the excavation volume of a pit divide into a grid with unequal intervals. From the characteristics of the cubic spline polynomial, the modeling curve of the Chen and Lin method is smooth and matches the ground profile well. Generally speaking, the nonlinear profile formulas provide better accuracy than the linear profile formulas. The mathematical model mentioned make an offer maximum accuracy in estimating the volume of a pit excavation.

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스플라인 기어류의 폐쇄단조 해석 (Closed-Die Forging Analysis of Spling-LikeComponents)

  • 이승동;김원일;김용조
    • 한국산업융합학회 논문집
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    • 제2권2호
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    • pp.187-194
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    • 1999
  • Closed-die forging of spline was analysed using the upper bound elemental technique, Two different forging methods, denoted here as side extrusion-forging and upset forging, were proposed, The kinematically admissible velocity fields for each of the forging methods, which could express trapezoidal, rectangular and serration tooth forms, were presented. Upper bounds to forging loads and deformed configurations were predicted using the velocity fields. Theoretical results were compared with experimental ones. Experiments with lead were carried out at room temperature where grease was used as a lubricant. The present investigation revealed that analytical forging loads were reduced by using the side extrusion-forging but the upset forging could improve configuration of the final forged splines.

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고온에서 맞물려 회전하는 토크컨버터 부품간 열 및 토크를 고려한 치형상의 최적설계 (Optimum Design of Teeth Shapes of Rotating Serration and Spline-type Torque Converter Parts Operating in a High Temperature Fluids)

  • 이동욱;김철;김정준;신순철
    • 대한기계학회논문집A
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    • 제41권11호
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    • pp.1125-1130
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    • 2017
  • $170^{\circ}C$의 고온에서 작동하는 자동변속기 토크컨버터의 리액터와 끝단 레이스 두 부품간 이빨이 서로 맞닿는 부분의 응력을 분산시키고, 수명을 증가시키기 위하여 치(이빨), 스플라인 두 형태의 리액터의 치형상을 FEM 최적화하였다. 최적화에 선행하여 서로 다른 재료로 된 두 부품의 열팽창에 의한 간격을 해석하였으며, 그 결과 열팽창 후에 치형 리액터는 약 0.1 mm, 스플라인형 리액터는 약 0.08 mm의 추가 간격이 발생한다는 것을 확인하였다. 형상최적화 결과 두 가지 형태의 리액터 치가 모두 비대칭 사다리꼴 형상으로 최적화 되었다. 이로 인해 치형 리액터의 경우 기존 비최적화 모델 대비, 최대등가응력이 24.5 % 감소하였으며, 스플라인형 리액터는 기존 비최적화 모델 대비 최대등가응력은 9.3 % 감소하였으며, 축 방향 두께는 13 % 감소하였다.

보간법을 이용한 디지털 방사선영상에서 치아 및 지지구조물의 ROC평가 (Evaluation of Teeth and Supporting Structures on Digital Radiograms using Interpolation Methods)

  • 고광준;장기완
    • 치과방사선
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    • 제29권1호
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    • pp.65-85
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    • 1999
  • Objectives: To determine the effect of interpolation functions when processing the digital periapical images. Material and Methods: The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods, and ROC curves were obtained by trapezoidal methods. Results: The heighest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The heighest Az value (0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at a=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at α=0.1 level.

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스플라인 곡면을 이용한 토공량 결정에 관한 연구 (On the Earthwork Volume Decision Using Spline Surfaces)

  • 류재칠;이승훈;문두열
    • 한국측량학회지
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    • 제20권1호
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    • pp.85-92
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    • 2002
  • 건설시공현장에서 토공량 결정은 전체공사비 중에 큰 비중을 차지하므로 정확한 계산방법이 있어야 한다. 토공량을 계산하는 현행방법은 격자점 사이의 횡단면의 간격을 선형(사다리꼴법칙)이나 비선형(심프슨법칙)으로 가정한다. 일반적으로 비선형법칙이 선형법칙보다 더 정확한 것으로 나타나 있다. 그러나 앞에서 언급된 모든 방법은 예리한 코너부분이나 두 점 사이의 갑작스런 지형변화에 대처할 수 없는 결점을 내포하고 있다. 본 논문에서는 B-스플라인을 이용하여 주어진 데이터를 지나는 스플라인 곡면을 구하는 알고리즘을 살펴보고, 스플라인 곡면을 이용하여 토공량을 근사적으로 구하는 방법을 제시한다. 스플라인 곡면을 이용한 방법이 Chen 과 Lin이 제시한 방법보다 더 정확함을 몇 가지 예를 통해 보인다.

Spline보간법을 이용한 토공량결정에 관한 연구 (A Study on the Earthwork Volume Decision using the Spline Interpolation)

  • 문두열
    • 한국측량학회지
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    • 제18권3호
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    • pp.305-313
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    • 2000
  • 건설시공현장에서 토공량결정은 전체공사비 중에 큰 비중을 차지하므로 정확한 계산방법이 있어야 한다 토공량을 계산하는 현행방법은 격자점사이의 횡단면의 간격을 선형 (사다리꼴법칙)이나 비선형(심프슨법칙)으로 가정한다. 일반적으로 비선형법칙이 선형법칙보다 더 정확한 것으로 나타나 있다. 그러나 앞에서 언급된 모든 방법은 예리한 코너부분이나 두점 사이의 갑작스런 지형변화에 대처할 수 없는 결점을 내포하고 있다. 본 연구에서는 일정 구역의 양방향에 splin법을 적용한 식을 구하였으며, 점고법, Chamber법, 그리고 Chen과 Lin법을 서로 비교하였다. 그 결과 제시된 방법은 기존의 방법들 보다 더 정확하였다. 또한, 제시된 수학적모델법은 현행식들의 정확도 평가에 기준이 된다.

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