• Title/Summary/Keyword: 3D-FEM

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Finite element analysis of carbon fiber-reinforced polymer (CFRP) strengthened reinforced concrete beams

  • Kim, SangHun;Aboutaha, Riyad S.
    • Computers and Concrete
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    • v.1 no.4
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    • pp.401-416
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    • 2004
  • This paper presents investigation of a three-dimensional (3-D) nonlinear finite element model analysis to examine the behavior of reinforced concrete beams strengthened with Carbon Fiber Reinforced Polymer (CFRP) composites to enhance the flexural capacity and ductility of the beams. Three-dimensional nonlinear finite element models were developed between the internal reinforcement and concrete using a smeared relationship. In addition, bond models between the concrete surface and CFRP composite were developed using a smeared bond for general analyses and a contact bond for sensitivity analyses. The results of the FEA were compared with the experimental data on full-scale members. The results of two finite-element bonding models showed good agreement with those of the experimental tests.

A study on the Vertical Earth Pressure in rigid buried pipe by numerical approach (강성매설관에 작용하는 연직토압에 관한 수치적 연구)

  • Park Sang-Won;Han Myung-Sik
    • Proceedings of the KSR Conference
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    • 2005.05a
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    • pp.661-666
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    • 2005
  • In this Paper, to calculate vertical earth pressure affected from several factors in case of rigid buried pipe with cohesionless backfill soil. The result from PENTAGON 3D is compared with several equation's result such as the Janssen, Marston, Spangler, Handy's equation. Result of study shows that vertical earth pressure of each equation is affected by backfill width, backfill depth and wall friction. And vertical earth pressure is linearly increased with backfill depth and backfill width. Marston's equation and Handy's equation are overestimated and FEM(Finite Element method) analysis and Janssen's Silo equation are affected by more backfill depth than backfill width.

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A Study on the Optimal die angle of the Torsional Forward Extrusion Process (비틀림 전방압출 공정의 최적다이각에 관한 연구)

  • Lee S. I.;Kim Y. H.;Ma Xiang
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.11a
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    • pp.23-32
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    • 2002
  • The torsional forward extrusion is the process that is executed by punch travel and die rotation. The advantages of having the die rotation on this process are that forming load can be reduced and optimal die angle can be increased. This provides a possibility to extrude cold-worded material where a large extrusion force and die angle are required. Also, this process can improve the material properties owing to the high deformation and uniform strain distribution. The forming load and optimal die angle of this process are determined by the upper bound analysis using stream function and the optimization technique. To verify the theoretical result, we have carried out experiments and FE simulations using DEFORM3D.

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Design of quadruple-clad, dispersion-flattened optical fibers with ultra-low dispersion at ${\lambda}=1.55{\mu}m$ (${\lambda}=1.55{\mu}m$에서 극저분산을 갖는 사중-클래드 평탄분산 광섬유의 설계)

  • 정석원;김창민
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.8
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    • pp.140-152
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    • 1995
  • Derived was the scalar wave equation of optical fibers. Based on the derived equation, the dispersion characteristics of arbitrarily profiled fibers were analyzed. We applied the 1-D FEM employing quadratic interpolation fucntions to solve the scalar wave equation. To find the optimum index distribution of a fiber that has the ultra-low total dispersion, we analyzed QC fibers as objects. Adding 2$_{nd}$ and 3$_{rd}$ clads to DC fiber, we investigated the change of dispersion characteristics. We found the QC fiber parameters for which the dispersion was ultra-low flattened, less than 0.5 ps/km.nm for ${\lambda}=1.4~1.6{\mu}m$, and the dispersion value was as low as 0.20 ps/km.nm at ${\lambda}=1.55{\mu}m$.

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Design and Fabrication of Piezoelectric MEMS Power Generator (압전 MEMS 발전기 설계 및 제작)

  • Nam, Woon-Woo;Park, Jong-Cheol;Park, Jae-Yeong;Jang, Young-Soo;Lee, Yoon-Pyo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1456-1457
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    • 2008
  • 본 논문에서는 박막 PZT(Pb(Zr,Ti)O3)를 이용한 d33모드의 자가 발전 소자를 설계 및 제작 하였다. 자가 발전 소자는 진동 에너지를 압전 현상을 통해 전기 에너지로 변환하는 소자로서, 제안한 구조는 단일 외팔보가 아닌 20개 이상의 외팔보를 원형으로 집적한 구조를 갖기 때문에, 기존의 단일 외팔보 위주의 자가발전 소자보다 출력 전력이 우수하다. 자가 발전 소자의 성능 최적화를 위해 유한요소기법(FEM)을 통해 기계적 특성을 분석하였으며, 마이크로 머시닝 기법을 이용하여 초박형의 자가 발전 소자를 제작할 수 있었다. 제작된 자가발전 소자는 $1.2mm\times1.2mm\times0.5mm$ (높이)의 크기를 갖는다.

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Collapse Characteristics of vehicle Members with Spot Welded Hat-Shaped Section under Axial Compression (점용접된 차체구조용 모자형 단면부재의 축방향 압궤특성)

  • 차천석;양인영;전형주;김용우;김정호
    • Journal of the Korean Society of Safety
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    • v.15 no.4
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    • pp.20-27
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    • 2000
  • The hat shaped section members, spot welded strength resisting structures are the most energy absorbing ones of automobile components during the front-end collision. Under the static axial collapse load in velocity of 10mm/min and quasi-static collapse load in velocity of 1000mm/min, the collapse characteristics of the hat shaped section and double hat shaped section member have been analyzed by axial collapse tests with respect to the variations of spot weld pitches on the flanges. In addition, the quasi-static collapse simulations have been implemented in the same condition to the experiment's using FEM package, LS-DYNA3D. The simulated results have been verified in comparison with these from the quasi-static axial collapse tests. With the computational approaches the optimal energy absorbing structures can be suggested. Simulations are so helpful that the optimized data be supplied in designing vehicles in advance.

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A Study on Roll Wear in the Roll Forming Process (롤포밍 공정에서의 롤 마모에 관한 연구)

  • Kang, Byung-Seok;Kim, Nak-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.11
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    • pp.1881-1888
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    • 2003
  • This study show a numerical method to predict roll wear in the roll forming process. Archard's wear model was reformulated in an elemental form to predict volume of roll wear and then wear depth on the roll was calculated using the results of finite element analysis. Abrasive wear occurs at contact area in the roll forming process and the results of simulation are compared with experimental data in production line. The wear simulation approach with 3-D FEM program for roll forming process, SHAPE-RF is in good agreement with it in tendency.

A Study on the Dynamic Analysis in the Shaft of Turbo-Blower for Fuel Cell (연료전지용 터보압축기 회전축의 동특성 해석에 관한 연구)

  • 김홍건;나석찬;김성철;강영우;양균의;이희관;최문창
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.1
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    • pp.81-87
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    • 2004
  • A 3-D FEM (Finite Element Method) analysis of the turbo-blower shaft attached to a fuel cell was performed using Lanczos algorithm. The modal analysis was analyzed in order to investigate natural frequency and maximum displacement for 10 times. It was found that the first mode of natural frequency is 109.1Hz with the maximum displacement of 0.16mm while the tenth mode of natural frequency is 2464Hz with the maximum displacement of 0.25mm. Consequently, the results of modal analysis of the turbo-blower for a fuel cell system show good dynamic responses.

Transient Response Analysis of Cylindrical Liquid Fuel-Storage Tank subject to Initial Acceleration (원통형 액체 연료탱크의 초기 가속에 따른 과도응답 해석)

  • Lee, S.Y.;Joo, Y.S.;Kim, K.W.;Cho, J.R.
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.475-480
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    • 2000
  • The transient dynamic-response analysis of fuel-storage tanks of flying vehicles accelerating in the vertical direction is achieved with finite element method. A fuel-storage tank is a representative example of the fluid-structure interaction problem, in which structure and fluid media interact strongly. For the accurate analysis of this complicated fluid-structure system, we employed ALE(arbitrary Lagrangian-Eulerian) coupling method. Two types of fuel-storage tanks, one with two baffles and the other without baffle, are considered to examine the effect of baffles. The fuel-storage tank with baffles shows more uniform hydrodynamic pressure distribution, resulting effective stress in structural region and faster convergence from transient to steady states. MSC/Dytran, a commercial FEM software for the 3D coupled dynamic analysis, is used for this analysis.

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Model Analysis 횡자속 선형전동기의 적용분야에 따른 모델분석 (횡자속 선형전동기의 적용분야에 따른 모델분석)

  • Ryu, Ho-Gil;Lee, Jeong-Jong;Kim, Young-Kyoun;Hong, Jung-Pyo;Kang, Do-Hyun
    • Proceedings of the KIEE Conference
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    • 2002.11d
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    • pp.61-63
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    • 2002
  • At recently, it is regarded efficiency of the electric motor. and the development of the electric motor of new concept and research according to the development of new material and a elevation of magnetic property of magnetism material have been processed actively. One of the that, the transverse flux linear electric motor is studing actively about application method in many ways. because it has high power density and efficiency more than a induction motor. In this study we introduce apply field of the electromotor which follows Picture and find out the characteristic using the 3D Finite Element Method(FEM).

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