• Title/Summary/Keyword: membrane deformation

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A NOTE ON NEW METALLIC BONDING ORBITAL

  • Oh, Hung-Kuk
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1994.11a
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    • pp.156-162
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    • 1994
  • The existence of the elastic anisotropic channeling is based on the experimental evidences. The rotating electron pairs orbits play the role of basic bonding orbitals. The abnormal signals from ligand domain and train-membrane in cancer cell, Deformation in fatigue and creep at low stress, con duction, superconduction and semiconduction are all from the new metallic bonding orbital.

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Mechanosensitive Modulation of Receptor-Mediated Crossbridge Activation and Cytoskeletal Organization in Airway Smooth Muscle

  • Hai, Chi-Ming
    • Archives of Pharmacal Research
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    • v.23 no.6
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    • pp.535-547
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    • 2000
  • Recent findings indicate that mechanical strain (deformation) exerted by the extracellular matrix modulates activation of airway smooth muscle cells. Furthermore, cytoskeletal organization in airway smooth muscle appears to be dynamic, and subject to modulation by receptor activation and mechanical strain. Mechanosensitive modulation of crossbridge activation and cytoskeletal organization may represent intracellular feedback mechanisms that limit the shortening of airway smooth muscle during bronchoconstriction. Recent findings suggest that receptor-mediated signal transduction is the primary target of mechanosensitive modulation. Mechanical strain appears to regulate the number of functional G-proteins and/or phospholipase C enzymes in the cell membrane possibly by membrane trafficking and/or protein translocation. Dense plaques, membrane structures analogous to focal adhesions, appear to be the primary target of cytoskeletal regulation. Mechanical strain and receptor-binding appear to regulate the assembly and phosphorylation of dense plaque proteins in airway smooth muscle cells. Understanding these mechanisms may reveal new pharmacological targets for control1ing airway resistance in airway diseases.

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A Shape Finding and Cutting Pattern Determination for Membrane Structures (막 구조물에 관한 형상 탐색과 재단도 결정법)

  • Choi, Ho;Lee, Jang-Bog;Kim, Jae-Yeol;Sur, Sam-Uel;Kwon, Taek-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.175-182
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    • 1998
  • The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions : (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, (1) shape finding analysis formulation and an example, (2) cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

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A Study on the Structural Behavior of Cable Domes (케이블 돔의 구조적 거동 특성에 관한 연구)

  • 한상을;윤종현;이승훈;진영상;황보석
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.10a
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    • pp.151-158
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    • 2000
  • Cable dome that consists of three component such as cable, strut and fabric membrane has complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system and fabric membrane element is conceived as cladding roof material. One of the important problem of cable dome is to investigate the structural response from external load effect such as snow and wind. When cable dome is subjected to load each structural component has various special structural characteristics. One is that geometrical nonlinearity should be considered because large deformation is occurred from their flexible characteristic. The other is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper researches the physical structural response of cable dome structure and the structural behavior when failure occurred at a part of structure.

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Iterative global-local approach to consider the local effects in dynamic analysis of beams

  • Erkmen, R. Emre;Afnani, Ashkan
    • Coupled systems mechanics
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    • v.6 no.4
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    • pp.501-522
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    • 2017
  • This paper introduces a numerical procedure to incorporate elasto-plastic local deformation effects in the dynamic analysis of beams. The appealing feature is that simple beam type finite elements can be used for the global model which needs not to be altered by the localized elasto-plastic deformations. An overlapping local sophisticated 2D membrane model replaces the internal forces of the beam elements in the predefined region where the localized deformations take place. An iterative coupling technique is used to perform this replacement. Comparisons with full membrane analysis are provided in order to illustrate the accuracy and efficiency of the method developed herein. In this study, the membrane formulation is able to capture the elasto-plastic material behaviour based on the von Misses yield criterion and the associated flow rule for plane stress. The Newmark time integration method is adopted for the step-by-step dynamic analysis.

Achieve the mechanical strength of ceramic membrane using low temperature ceramic glaze (저온용 도자기 유약을 이용한 세라믹 분리막의 기계적 강도 증가)

  • Lee, Jong-Chan;Kim, Jin-Ho;Han, Kyu-Sung;Hwang, Kwang-Taek
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.1
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    • pp.38-43
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    • 2018
  • Ceramic membrane has been widely used for water treatment due to its advantages of eco-friendly property and low energy consumption. However, high porosity of ceramic membrane higher than 40 % may cause a problem of strength, when it is applied to a water treatment module. In order to solve this problem, the strength of the membrane edge was improved by using the ceramic glaze. Four different glaze compositions for low temperature sintering was selected to minimize the deformation of the membrane microstructure. After coating with low temperature glaze, cracks were observed due to differences in thermal expansion coefficient between the membrane and glaze. Thus, the thermal expansion coefficient of glaze was controlled by addition of cordierite and petalite. As a results, the compressive strength of the ceramic membrane, which was coated with the optimized glaze composition, was increased from $27N/m^2$ to $117N/m^2$, indicating that the glaze coating can improve the disadvantages of the fragile ceramic membrane.

The Modeling and Adaptive fuzzy control of Electrostrictive Polymer for endoscopic microcapsule (체내이동형 마이크로 캡술형 내시경 로봇을 위한 Electrostrictive Polymer의 모델링 및 Adaptive fuzzy 알고리듬 개발)

  • Hwang, Kyo-Il;Kim, Hun-Mo;Choi, Hyouk-Yeol;Nam, Jae-Do;Jeon, Jae-Wook
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.716-722
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    • 2001
  • In this paper, the modeling and control of electrostrictive polymer is introduced for endoscopic microcapsule. The endoscopic microcapsule works in the body, so the material of robot must be no harmful to the body. The electrostrictive polymer satisfies this condition. The modeling and control of endoscope microcapsule must be processed. So the modeling and control of electrostrictive was processed preferentially. The electrostrictive polymer is so flexible that we considered the electrostrictive polymer as flexible membrane. The dynamic equation of flexible membrane is time variant in electrostrictive polymer. It is the reason that the elastic modulus of electrostrictive polymer is very small and changes as deformation of electrostrictive polymer. The control algorithm must overcome these characteristics. So the algorithm of adaptive fuzzy control was used to control. In this paper, we introduced the dynamic modeling and control of electrostrictive polymer. And its deformation is introduced.

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Analysis of Deep Drawing of Planar Anisotropic Materials Using the Rigid- Plastic Finite Element Method (강소성 유한요소법을 이용한 평면 이방성 재료의 디프 드로잉 해석)

  • 김형종;김동원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.2
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    • pp.248-258
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    • 1992
  • Three-dimensional rigid-plastic finite element formulation based on the membrane theory was described and a computer program for large deformation analysis was developed. In the formulation, normal and planar anisotropy of sheet material and rotation of the principal axes of anisotropy was taken into consideration. Sheet metal was assumed to be rigid-plastic material obeying Hill's quadratic yield criterion and its associated flow rule. Deep drawing process, as a preliminary test, for normal anisotropic material was analyzed in order to examine the validity of developed finite element program. The results were consistent with the existing finite element solutions or experimental data. The present study was mainly concerned with the influence of planar anisotropy on deformation behaviour. Finite element analysis and experiment were carried out for the whole process of deep drawing of planar anisotropic material. The computational and experimental results on the shape of ear, strain distribution and punch load were in good agreement.

Dynamic Response of Triangular Solar Sail with Wrinkles (주름이 있는 삼각형 태양돛의 동적해석)

  • Bae, Hongsu;Woo, Kyeongsik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.3
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    • pp.195-203
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    • 2015
  • In this paper, the dynamic behavior of wrinkled triangular solar sail was studied by finite element analysis. The analysis was proceeded first by performing static wrinkle analysis under tensile corner load on sail membrane, and then performing modal analysis. The membrane element method with wrinkle algorithm and the shell element post-buckling analysis method were used to account for the wrinkle deformation and the results were compared for analysis methods throughly. The comparison was also made to that without wrinkle consideration to investigate the effect of wrinkle deformation on the results. Cases with various loading cable angles were analyzed and the results were systematically examined.

Dilatometer test for evaluating deformation characteristics in sand (사질토의 변형특성 평가를 위한 딜라토미터 시험의 활용)

  • Lee, Moon-Joo;Hong, Sung-Jin;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.241-252
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    • 2010
  • This study investigates the application of dilatometer test for evaluating the deformation characteristics of granular soil. $K_D$ is the most sensitive to the stress history among CPT and DMT measurements, and $E_D$ and $q_c$ are observed to be similarly affected by the stress history. The coefficient of at-rest earth pressure($K_0$) is an indirect measure evaluating the stress history of granular soil. A relation using only DMT indices provides appropriate prediction of $K_0$ values. Although penetration of dilatometer inevitably induces the failure of cementation bonds, $E_D$ reflects the deformation characteristics of undamaged cementation relatively well. Therefore, a slightly better prediction of M value for cemented sand is achieved by using $E_D$ rather than $q_c$. Because of the weaker particle strength of calcareous sand compared than quartz sand, the majority of sand particles adjacent to dilatometer probe will be crushed during penetration. The particle crushing will induce the less contraction of the dilatometer membrane during penetration, consequently, the smaller $K_D$ and $E_D$ of calcareous sand.

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