• Title/Summary/Keyword: NASTRAN/PATRAN

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Dynamic Characteristic Analysis of Tilting Turret Systems Using Finite Element Modeling (유한요소 모델링을 이용한 틸팅터릿 시스템의 진동특성해석)

  • 정상화;김재열;김상석;나윤철
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.5
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    • pp.60-70
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    • 2001
  • In multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret unit is modeled by considering the element dividing, material proprties, and boundary conditions with PATRAN. Normal mode and frequency analysis of each structures such as saddle, cared, and turret are simulated by NASTRAN, for the purpose of developing the effective design. The results of mode analysis and frequency analysis are visualized with PATRAN, and the design method which can solve the resornance problem by eigenvalues and eigenvectors of each axis is developed as well.

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A Technique for Calculations of Power Flow in Structures Using MSC/NASTRAN and PCL (MSC/NASTRAN 및 PCL을 이용한 구조물 내의 진동 파워 흐름 해석 기법)

  • 홍진숙
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.8
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    • pp.303-313
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    • 2001
  • The identification of power flow in dynamically loaded structures Is essential in the analysis of structure-borne noise. However there are no general purpose tools to estimate powers flow. To make matters worse. It is very difficult to measure it. The power flow can be formulated in terms of balance forces(ELFORCE) at each element and velocities at the associated node obtained with MSC/NASTHAN. In this paper the procedure which is consist of the computations of the balance forces of al1 elements and the velocities at all nodes using MSC/NASTRAN. The calculations of the power f1ow at each element using PCL(PATRAN Command Language) and the Preparation of post -processes is set UP.

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Analysis of Stiffness for Frustum-shaped Coil Spring (원추형 코일스프링의 강성해석)

  • Kim, Jin-Hun;Lee, Soo-Jong;Kim, Jung-Ryul
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.2
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    • pp.250-255
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    • 2008
  • Springs are widely utilized in machine element. To find out stiffness of frustum-shaped coil spring, the space beam theory using the finite element method is adopted in this paper. In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. To find out load vector of coil spring subjected to distributed compression. principle of virtual work is adapted. And this theory was programming using MATLAB software. To compare FEM using MATLAB software was applied MSC. Nastran software. The geometry model for MSC. Patran was produced by 3-D design modeling software. Finite element model was produced by MSC. Patran. Finite element was applied tetra (CTETRA) having 10 node. The analysis results of the MATLAB and MSC. Nastran are fairly well agreed with those of various experiments. Using MATLAB program proposed in this paper and MSC. Nastran, spring constants and stresses can be predicted by input of few factors.

FE Analysis of Movable Bearing Shoe and Hinged Bearing Shoe (입체요소를 이용한 가동받침과 고정받침의 유한요소해석)

  • 최창근;이태열;김태완;김재철
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.373-380
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    • 1998
  • 3D finite element analyses of movable bearing shoe and hinged bearing shoe are performed. The finite element models are built using MSC/PATRAN and analyses are carried out using MSC/NASTRAN. Results are again completely processed using MSC/PATRAN. From the results of the analyses, trends of deformation and stress distribution are reviewed and important factors to consider in the design of bearing shoes are discussed. Furthermore optimum crowning amount for the roller of movable bearing shoe was determined according to the results of the analyses.

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Structural analysis of a thick composite rotor hub system by using equivalent properties (등가 물성을 이용한 두꺼운 복합재 로터 허브 시스템의 구조 해석)

  • ;Yanti Rachmadini
    • Composites Research
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    • v.16 no.5
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    • pp.7-14
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    • 2003
  • Modeling of thick composite structures for finite element analysis is relatively complicated. 2-D plane elements may cause inaccurate result since the plane stress condition cannot be applicable in these structures. Therefore a 3-D modeling should be used. However, the difficulty to model all the layers with different material properties and ply orientation arise in this case. In this paper, an equivalent modeling is proposed and numerically tested for analysis of thick composite structures. By grouping layers with same material and ply orientation, number of elements through the thickness is remarkably reduced and still the result is close enough to the one from a detail finite element model. MSC/NASTRAN and PATRAN are used for the analysis. The proposed modeling technique has been applied for analysis of composite rotor hub system designed by Korea Aerospace Research Institute(KARI). Using the proposed equivalent modeling technique, we could conduct stress analysis for the hub system and check the safety factor of each part.

Tool Holder Design and Cutting Force Measurement of Diamond Turning Process (다이아몬드 터닝의 미세 절삭력 측정을 위한 tool holder 설계 및 절삭력 측정)

  • Jeong, S.H.;Kim, S.S.;Do, C.J.;Hong, K.H.;Kim, G.H.;Rui, B.J.
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.507-512
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    • 2001
  • In this work, tool holder system has been designed and builted to measure cutting forces in diamond turning. This system design includes a 3-component piezo-electric tranducer. Initial experiments with tool holder system included verification of its predicted dynamic characteristics as well as a detailed study of cutting parameters. Tool holder system is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of structure is simulated by MSC/NASTRAN, for the purpose of developing the effective design. Many cutting experiments have been conducted on 6061-T6 aluminum. Tests have involved investigation of velocity effects, and the effects of depth and feedrate on tool force. Forces generally increase with increasing depth of cut. Increasing feedrate does not necessarily lead to higher forces.

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Optimal Manufacturing of Composite Wing Ribs in Solar-Powered UAVs: A Study (태양광 무인기 복합재 윙 리브 최적 제작 연구)

  • Yang, Yongman;Kim, Myungjun;Kim, Jinsung;Lee, Sooyong
    • Journal of Aerospace System Engineering
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    • v.10 no.4
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    • pp.50-58
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    • 2016
  • In our preceding study, we reported that the use of light, composite-material wings in long-endurance Solar-Powered UAVs is a critical factor. Ribs are critical components of wings, which prevent buckling and torsion of the wing skin. This study was undertaken to design and manufacture optimal composite ribs. The ribs were manufactured by applying laminated-layer patterns and shapes, considering the anisotropic properties of the composite material. Through the finite element analysis using the MSC Patran/Nastran, the maximum load and the displacement shape were identified. Based on the study results measured by structural tests, we present an optimal design of ribs.

Measurement of Cutting Force in Diamond Turning Process (다이아몬드 터닝의 절삭력 측정용 tool holder를 이용한 미세절삭력 특성 연구)

  • 정상화;김상석;도철진;홍권희;김건희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.938-941
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    • 2001
  • A tool holder system has been designed and builted to measure cutting forces in diamond turning. This system design includes a 3-component piezo-electric tranducer. Initial experiments with tool holder system included verification of its predicted dynamic characteristics as well as a detailed study of cutting parameters. In this research, tool holder system is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of structure is simulated by MSC/NASTRAN, for the purpose of developing the effective design. In addition, tool holder system is verified by vibration test using accelerometer. Many cutting experiments have been conducted on 6061-T6 aluminum. Tests have involved investigation of velocity effects, and the effects of depth and feedrate on tool force. Cutting velocity has been determined to have negligible effects between 4 and 21㎧.(6) Forces generally increase with increasing depth of cut. Increasing feedrate does not necessarily lead to higher forces. Results suggest that a sample model may not be sufficient to describe the forces produced in the diamond turning process.

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A Study of Flutter Analysis for the Composite Box Wings with Various Laminates (다양한 적층각에 대한 상자형 복합재료 날개의 플러터 특성연구)

  • Chung, Y.H.;Kwon, H.J.;Kim, D.H.;Lee, I.;Kim, C.G.
    • Composites Research
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    • v.15 no.1
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    • pp.1-8
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    • 2002
  • In this study, the flutter analysis for a rectangular box wing and an actual fighter wing with composite shin, aluminum spar and aluminum rib has been conducted. A conservative 3D wing-box model of an actual wing is modeled by MSC/PATRAN and the corresponding free vibration analysis has been performed by MSC/NASTRAN. The finite elements of membrane, rod and shear panel are used. Using the practical ply angles, various composite laminates are composed and analysed. The DLM code which is linear aerodynamic theory in frequency domain is applied to calculate unsteady aerodynamic pressure in subsonic flow region and the V-g and p-k methods are applied to obtain the solution of aeroelastic governing equation in frequency domain.

Study on Flow Property and Structural Analysis of Gas Generator Oxidizer On/Off Valve (가스발생기 산화제 개폐밸브의 내부 유동특성 및 구조해석에 관한 연구)

  • Lee, Jongl-Yul;Huh, Hwan-Il;Ahn, Yang-Woo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.6
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    • pp.48-55
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    • 2009
  • The purpose of using Gas Generator Oxidizer On/Off Valve(GOV) is to control opening and closing of oxidizer mass flow. This paper describes analytical results of flow and structural properties for four different GOV models, using commercial software such as Fluent(Ver. 6.3.26) and NASTRAN(2005 r.2), PATRAN(2005 r.2). Analytical results show that GOVs could generate 2.3~3.8 kg/s of oxidizer mass flow rate and come up with 1.09~1.42 of safety factor.