• Title/Summary/Keyword: Deflection characteristics

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A review of numerical approach for dynamic response of strain gradient metal foam shells under constant velocity moving loads

  • Fenjan, Raad M.;Ahmed, Ridha A.;Hamad, Luay Badr;Faleh, Nadhim M.
    • Advances in Computational Design
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    • v.5 no.4
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    • pp.349-362
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    • 2020
  • Dynamic characteristics of a scale-dependent porous metal foam cylindrical shell under a traveling load have been explored within this article based on a numerical approach. Within the material texture of the metal foams, uniform and non-uniform porosities may be dispersed. Based upon differential quadrature method (DQM) and Laplace transforms, the equations of motion for a shear deformable scale-dependent shell may be solved numerically. Scale-dependent shell modeling has been provided based upon strain gradient elasticity. Solving the equations will give the shell deflection as a function of load speed. Also, it is reported that shell deflection relies on the porosity dispersion and strain gradient influences.

Structural Characteristics of a Hybrid Composite Carbody of Korean Tilting Train by Weight Load (한국형 틸팅열차용 복합재 차체의 하중적재에 따른 구조적 특성고찰)

  • Kim Jung-Seok;Jeong Jong Cheol;Han Jeong-Woo;Lee Sang-Jin;Kim Seung-Cheol;Seo Sung-Il
    • Journal of the Korean Society for Railway
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    • v.9 no.3 s.34
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    • pp.251-256
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    • 2006
  • This paper explains manufacturing process, analysis and experimental studies on a hybrid composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of a aluminium honeycomb core and woven fabric carbon/epoxy faces. In order to evaluate deformational behavior of the composite carbody, the static load test under vertical load has been conducted. From the test, the vertical deflection an겨 cross sectional deformation of the carbody were analysed and measured. The maximum deflection along the side sill was 9.25mm in the experiment and 8.28mm in the analysis. The maximum cross sectional deformation was measured 5.42mm at carbody center in lateral direction and 4.06mm at roof center in vertical direction.

Theoretical and Finite Element Analysis for Structural Strength of Paperboard-stacked Structure (종이성형구조물의 구조적 강도에 대한 이론분석과 유한요소해석)

  • Park, Jong-Min;Lee, Myung-Hoon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.5 no.1
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    • pp.13-20
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    • 1999
  • Not only is it important that the physical properties of the paperboards be appropriate for the intended end use, but the proper arrangement of the component in the built-up board is essential for attaining the optimum moment of inertia and the maximum load-carrying ability in a box. It is known to be impossible to estimate the stress distribution and deflection pattern by experiments or theoretical analysis when the corrugated fiberboard get the bending force. This study was tried theoretical and finite element analysis to analyze structural strength characteristics of corrugated fiberboards. If the linerboard and corrugating medium of every corrugated fiberboards is made from the same material, the location of neutral axis comes close to inside liner in order of DMA, DM, DMB, SW and DW, and moment of inertia of area decreases in order of DMA, DMB, DW, DM and SW. With the finite element analysis, deflection of applied loads represented SW, DM, DMA, and TW in the order of their value.

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Statics and Free Vibration Characteristics of Rectangular Plates Made of Functionally Graded Materials (경사기능재료 사각평판의 정적 및 진동해석)

  • 민준식;송오섭;이윤규;정남희;강호식
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.439-445
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    • 2003
  • In the recent years, functionally graded materials(FGM) have gained considerable attention in the high temperature environment applications. In the present work, study of the deflection and vibration of a functionally graded rectangular plate made of Ti-6Al-4V and Al$_2$O$_3$ is presented. Material properties are graded in the thickness direction of the plate according to volume fraction power law distribution Effects of volume fractions(power law exponent) on the deflection and natural frequency of FGM plate is studied. Also effects of temperature is studied. Wavier Solution is used to analyzed the FGM plate.

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Elasto-Hydrodynamic Lubrication Characteristics of Bump Foil Bearings (범프포일베어링의 탄성유체윤활 특성)

  • Kim, Young-Cheol;Lee, Dong-Hyun;Kim, Kyung-Woong
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.98-103
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    • 2004
  • This paper presents modeling and simulation of the bump foil bearings with consideration of the elastic behavior of the foil and gas compressibility. Heshmat had originally introduced the simple compliance model to estimate the EHL(elasto-hydrodynamic lubrication) performance. But this approach can not consider the deflection of top foil at the edge of bearing, so model is insufficient to analyze in case that the eccentricity ratio is greater than I. So the top foil is considered as a simple beam model supported by linear spring elements, and the bump foil deflection can be simple compliance model. The EHL calculations are performed for convention rigid type, classical foil type, variable pitch type and double bump type toil bearings. This paper presents that 2nd or 3rd generation bearings have excellent performance in every speeds.

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An Analytical Study on the Bond-Properties of Axial Bars Embedded in Massive Concrete (매시브콘크리트에 배근된 주철근의 부착특성에 관한 해석적 연구)

  • 장일영;이호범;이승훈;변근주
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.143-147
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    • 1992
  • Description of the behavior of the R.C structural members fixed on massive concrete is not normally generalization of recognized configuration for regular R.C. design guidanes. This can be due to the complexity of evaluation of internal resistancy and deflection changes of the members subjected to the various external forces. On the base of axially loaded member fixed on footing, however, the estimation of deflection changes due to flexural force shear force and rotational force is to be carried out in ways of specifying the bond characteristics of axial bars embedded in massive concrete. This work is to quantify adhesion of steel-concrete, initial concrete cracking stress near bar rib, maximum bond stress and residual stress in concrete respectively. In addition to quantification of them for particulate behavior, the suggestions of multi-linear bond stress-slip diagram made in carrying out finite element analyses for adhesion failure, examining concrete cracking status and reviewing existing experimental data lead to alternatively constructed relationship between bond stress and slip for a axial bars embedded massive concrete.

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Thermal postbuckling and vibration analyses of functionally graded plates (경사기능판의 열적 후좌굴 및 진동해석)

  • Park Jae-Sang;Kim Ji-Hwan
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.279-283
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    • 2004
  • Thermal postbuckling and vibration analyses of functionally graded plates (FG plates) are performed. The nonlinear finite element equation based on the first-order shear deformation plate theory is formulated for the FG plate. The von Karman strain-displacement relation is used to account for the thermal large deflection. The incremental method considering the effect of the initial deflection and the initial stress is adopted for temperature-dependent material properties of functionally graded materials. The numerical result shows characteristics of the thermal postbuckling and vibration of FG plates in the pre- and post- buckled regions.

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Structural and Sound Field Analysis of the High Speed CD-ROM Disk Drive (고속 CD-ROM Drive의 구조 및 음장 해석)

  • Yim, Woong-Sub;Cha, Sung-Woon;Lee, Jae-Seung;Moon, Yong-Rak
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.210-215
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    • 2001
  • CD-ROM Drives Rotating high speed as 10000 rpm cause serious noise and vibration problems. At the high speed, dominant noise is Air Borne Noise produced from high-speed airflow and Structure Borne Noise produced from structural vibration. In this research, vibration and sound characteristics in CD-ROM Drive were studied by the use of experimental analysis and computational simulation. Sound intensity techniques and ODS(Operational Deflection Shape) techniques are applied to identify the acoustic noise source of CD-ROM drive. And Computational simulation using SYSNOISE is conducted for describing the noise behavior.

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Development of Serviceability Model for RC Flexural Members (철근콘크리트 휨부재의 사용성 모델 개발)

  • Lee, Ki-Yeol;Kim, Jang-Hyun;Ha, Tae-Gwan;Kim, Dae-Joong;Kim, Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.413-416
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    • 2004
  • This paper describes a proposal for crack width and deflection in RC flexural members. Because the serviceability provisions of the current codes are mainly based on only empirical relationships developed from test result and effective moment of inertia, crack width and deflections are contrary to the actual values. Based on nonlinear bond characteristics, tension stiffening effect, arch action and effective concrete tensile area. Then an equation is developed for predicting crack width and deflection in flexural members. The predicted results shows that as proposed model employed, crack width and deflections are different from estimated by the current KCI, MC 90 and EC 2 provisons, and the values predicted are in good agreement with experimentally measured values.

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Performance sensitivity analysis of feedback system for adaptive control of a vehicle suspension (자동차 현가장치의 적응제어를 위한 feedback 시스템의 성능감도 해석)

  • Park, H;Jeon, E. S.;Oh, J. E.
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.35-45
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    • 1991
  • A linear quarter model of a vehicle suspension system is built and simulated. Especially the so-called sensitivity analysis is conducted in order to show its applicability to design problems, and sensitivity function is determined in the frequency domain. The change of frequency response function is predicted, which depends on the design parameter variation and the property is verified by computer simulation. Typical performance measures, namely, sprung mass acceleration, suspension deflection, and tire deflection are examined. The vehicle model is analyzed for ist performance sensitivity as a function of the system's feedback gains. The variable feedback gains are selected as the spring and damping coefficients. Frequency response, RMS response, and performance index of the performance evaluation variables are considered and three-dimensional and contour plots of response surfaces are formed to examine output sensitivity to suspension feedback. Performance trade-offs over the entire frequency spectrum are identified from the FRF, and that between ride quality and handling characteristics are examined from the RMS responses.

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