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Готові списки джерел за темами / Compressive membrane action

Добірка наукової літератури з теми "Compressive membrane action"

Автор: Grafiati

Опубліковано: 14 березня 2023

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Статті в журналах з теми "Compressive membrane action"

1

Das, S. K., and C. T. Morley. "Compressive membrane action in circular reinforced slabs." International Journal of Mechanical Sciences 47, no. 10 (October 2005): 1629–47. http://dx.doi.org/10.1016/j.ijmecsci.2005.04.007.

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2

Vecchio, F. J., and K. Tang. "Membrane action in reinforced concrete slabs." Canadian Journal of Civil Engineering 17, no. 5 (October 1, 1990): 686–97. http://dx.doi.org/10.1139/l90-082.

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The formation and influence of compressive membrane action in reinforced concrete slabs is discussed. An experimental program is described, in which two large-scale slab specimens were tested under concentrated midspan loads. One slab was restrained against lateral expansion at the ends, while the other was free to elongate. The laterally restrained specimen developed high axial compressive forces, which resulted in a significant increase in flexural stiffness and load capacity. A nonlinear analysis procedure was used to model specimen behaviour. The analysis method was found to adequately represent important second-order effects, and thus gave reasonably accurate predictions of load–deformation response and ultimate load. Key words: analysis, concrete, deformation, load, membrane, reinforced, slabs, strength, tests.

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3

Zheng, Y., D. Robinson, S. Taylor, D. Cleland, and A. Shaat. "Analysis of compressive membrane action in concrete slabs." Proceedings of the Institution of Civil Engineers - Bridge Engineering 161, no. 1 (March 2008): 21–31. http://dx.doi.org/10.1680/bren.2008.161.1.21.

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4

Zeng, Yihua, Robby Caspeele, and Luc Taerwe. "Compressive Membrane Action in FRP-strengthened Concrete Beams." IABSE Symposium Report 104, no. 17 (May 13, 2015): 1–5. http://dx.doi.org/10.2749/222137815815774980.

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5

Zeng, Yihua, Robby Caspeele, Stijn Matthys, and Luc Taerwe. "Compressive membrane action in FRP strengthened RC members." Construction and Building Materials 126 (November 2016): 442–52. http://dx.doi.org/10.1016/j.conbuildmat.2016.09.061.

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6

Thoma, K., and F. Malisia. "Compressive membrane action in RC one-way slabs." Engineering Structures 171 (September 2018): 395–404. http://dx.doi.org/10.1016/j.engstruct.2018.05.051.

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7

Collings, David. "Unlocking the potential of compressive membrane action in concrete." Proceedings of the Institution of Civil Engineers - Civil Engineering 170, no. 1 (February 2017): 12. http://dx.doi.org/10.1680/jcien.2017.170.1.12.

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8

Hon, Alan, Geoff Taplin, and Riadh Al-Mahaidi. "Compressive membrane action in reinforced concrete one-way slabs." Australian Journal of Structural Engineering 5, no. 3 (January 2004): 153–70. http://dx.doi.org/10.1080/13287982.2004.11464935.

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9

Thienpont, Thomas, Ruben Van Coile, Wouter De Corte, and Robby Caspeele. "Structural reliability of hollow core slabs considering compressive membrane action." Acta Polytechnica CTU Proceedings 36 (August 18, 2022): 237–43. http://dx.doi.org/10.14311/app.2022.36.0237.

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Анотація:

Compressive membrane action can considerably improve the load bearing capacity of concrete slabs and beams in case of excessive loaded due to an accidental event. Currently, only limited research has been focusing on compressive membrane action in prestressed concrete elements, or on concrete elements with large cavities, such as precast concrete hollow core slabs. Therefore, a novel real-scale test setup has been developed in order to assess this effect in precast hollow core slabs, and how it can enhance the load-carrying capacity in accidental events. In parallel with these tests, a numerical finite element model has been developed in order to perform a more detailed structural analysis of this phenomenon, and to study the influence of various input parameters. The details of this test setup are briefly explained, and some relevant experimental test results are provided. Considering the experimental findings and validated numerical model, this contribution aims to quantify the influence of compressive membrane action on the structural reliability of precast concrete hollow core slabs. To this end, probabilistic models for the most important material and geometric variables are gathered, and the structural reliability is assessed using Latin Hypercube sampling. Overall, the results indicate that considering the formation of compressive membrane action strongly influences the variability of the ultimate load-carrying capacity of precast concrete hollow core slabs.

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10

Punton, Ben M., Mike P. Byfield, and Peter P. Smith. "Load Redistribution Using Compressive Membrane Action in Reinforced Concrete Buildings." Applied Mechanics and Materials 82 (July 2011): 272–77. http://dx.doi.org/10.4028/www.scientific.net/amm.82.272.

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The primary function of any designed structure is to be able to support pre-determined static loads which allow the building to be occupied for its intended use. In the design process the unlikely event that the building is damaged must be considered. Often the focus is directed to the loss of primary loading elements that are fundamental to the integrity of the structure. The damage that is caused as a consequence may propagate causing collapse of surrounding elements culminating with the loss of an extensive proportion of the floor area. To prevent collapse inherent alternative load paths can be utilised. Both the elastic and plastic approved methods for the design of reinforced concrete in modern codes of practice neglect the effect of membrane forces. It has been recognised for some time that the omission of compressive membrane action (CMA), also described as ‘arching action’, can lead to a significant underestimation of load capacity. Previous studies which have attempted to determine if CMA is capable of supporting damaged columns under accidental loading conditions have not had supporting experimental testing of slabs at appropriate span to depth ratios. This paper presents an experimental program conducted on laterally restrained slab strips at approximately half scale. Combined with an analytical study, the extent to which CMA can be used as an effective robustness tool has been assessed.

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Більше джерел

Дисертації з теми "Compressive membrane action"

1

Lahlouh, El-hachemi. "Compressive membrane action in concrete silos." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280887.

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2

Tharmarajah, G. "Compressive membrane action in FRP reinforced slabs." Thesis, Queen's University Belfast, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546437.

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3

Jackson, Paul Austin. "Compressive membrane action in bridge deck slabs." Thesis, University of Plymouth, 1989. http://hdl.handle.net/10026.1/2622.

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An elastic analysis of restrained slab strips shows that membrane action enhances serviceability behaviour. However, the enhancement is not as great as for strength and serviceability is critical when membrane action is considered in design. A relatively simple form of non-linear finite element analysis is developed which is able to model bridge deck behaviour allowing for membrane action. This reduces some of the disadvantages of non-linear analysis which have prevented its use in practice. It uses line elements but, because of novel features of the elements and because it considers all six degrees of freedom at each node, it is still able to model in-plane forces reasonably realistically. It gives acceptable predictions for behaviour. The tension stiffening functions used in non-linear analysis, which are important to the prediction of restraint, are considered. Explanations are proposed for several aspects of the behaviour and a-new function is developed. This gives better results than previous expressions, particularly for deflections on unloading and reloading. Tests under full HB load have been performed on two half scale bridges. These, and the analysis, show that conventional design methods for deck slab reinforcement are very conservative. They also show that the restraint required to develop membrane action is not dependent on diaphragms; it comes from under-stressed material surrounding the critical areas. Thus, over much of a bridge's span, there Is transverse tension in the slab and membrane action does not significantly enhance the resistance to global moments. Both bridge models failed by a wheel punching through the slab. It is shown that these were primarily brittle bending compression failures which were strongly influenced by global behaviour. This is confirmed both by the analysis and by the higher wheel load at failure in single wheel tests. Recommendations are made for using the results in design and assessment.

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4

Taylor, Susan Elizabeth. "Compressive membrane action in high strength concrete bridge deck slabs." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314163.

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5

Kuang, Jun Shang. "Punching shear failure of concrete slabs with compressive membrane action." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240241.

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6

Hon, Alan 1976. "Compressive membrane action in reinforced concrete beam-and-slab bridge decks." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/5629.

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7

Eyre, John Richard. "Strength enhancement in reinforced concrete slabs due to compressive membrane action." Thesis, University College London (University of London), 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318494.

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8

Niblock, Robin Alexander. "Compressive membrane action and the ultimate capacity of uniformly loaded reinforced concrete slabs." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232970.

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9

LA, MAZZA DARIO. "Numerical models for the robustness assessment of reinforced concrete framed buildings." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2712599.

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Cast in situ reinforced concrete frame is one of the most common options for civil buildings. Although earliest common usages of this solution date back to second half of 19th century, research activity is constantly developing to investigate several aspects, especially about nonlinear behaviour of reinforced concrete structures. Structural robustness of buildings is actually one of the key issues faced by the international scientific community. This expression is used to indicate a desirable property of a structure that allows it to withstand an accidental event, preventing progressive and/or disproportionate collapse. Interest in this topic has been growing rapidly after the collapse of Ronan Point Apartment Tower in Newham, East London, in 1968, when a gas explosion destroyed a loadbearing concrete panel causing the collapse of an entire corner of the building. Although the issue of progressive collapse of multi-storey frames has been widely studied in the last decades, according to the literature review, the actual structural response after a localised failure has not yet been fully understood. Besides, many design guidelines for preventing progressive collapse denote a lack of adequate theoretical supports. Several technics have been developed to evaluate the response after an accidental situation. In Europe, EN1991-1-7 has introduced the notional removal design strategy. This approach establishes that a building should be checked to ensure that upon the notional removal of each column or each beam supporting a column, or any nominal section of load-bearing wall, one at a time in each storey of the building, the structure remains stable exhibiting only localised failure. Currently one of the main solution to ensure robustness consists in tying together structural members by using continuous reinforcement. In this context, the designer is required to evaluate the global structural response, then the role played by the floor-system becomes crucial. However, this operation involves longer times for modelling and analyses. The study here presented is articulated through several points. The initial intent is to develop simplified models of the floor-system able to simulate its behaviour, to obtain accurate results through a more efficient modelling. Different numerical models will be presented. These will focus on distinct simplification levels, depending on the finite elements adopted. The codes used for nonlinear numerical analyses have been previously tested and validated on experimental tests on 2D and 3D specimens and both static and dynamic analyses. The second aim is to evaluate the effectiveness of different floor-system typologies on the global behaviour of reinforced concrete frames. Two typical reinforced concrete solutions are tested: the first exploits a bidirectional slab, while the second uses monodirectional joists with a collaborating slab. To compare the results, a structure with features common to most of the reinforced concrete buildings has been chosen as reference test. The considered scenarios involve the removal of four distinct columns: two internal ones with different boundary conditions, an edge column and a corner column, all the elements are placed at the ground floor level. The third aim is to evaluate the influence of several parameters on global response, to identify their possible influence on the phenomenon and to highlight which among these have a determining impact on the structural response. The factors investigated are: primary beams depth, columns depth, presence of bracing systems, continuous reinforcement amount and seismic detailing. The achieved results provide precise information on the overall structural behaviour, highlighting the key role played by certain factors such as the percentage of continuous reinforcement in the beams and the importance of seismic detailing. At the same time the analyses have highlighted the marginal influence exerted by other parameters like the stiffening contribution given by a bracing system or stiffer columns, whose effects may be considered negligible.

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10

Schäfer, Edith Elisabeth. "Mechanik und Dynamik biologischer Modellsysteme am Beispiel aktingefüllter Vesikel und synchroner Zellmigration von Dictyostelium discoideum." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-F6D2-3.

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Diese Arbeit beschäftigt sich mit zwei verschiedenen Modellsystemen, die Aufschluss über die Mechanik und die Dynamik von zellulären Systemen geben sollen. Zum Einsatz kommt zum einen der Modellorganismus Dictyostelium discoideum, dessen kollektives Migrationsverhalten analysiert wird und zum anderen wird die Mechanik von aktingefüllten Riesenvesikeln als artifizielles Modellsystem etabliert.

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Книги з теми "Compressive membrane action"

1

Niblock, Robin Alexander. Compressive membrane action and the ultimate capacity of uniformly loaded reinforced concrete slabs. 1986.

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2

England, Highways. Design Manual for Roads and Bridges : Vol. 3 : Highways Structures : Inspection and Maintenance, Section 4 : Assessment, Part 20: Use of Compressive Membrane Action in Bridge Decks. Stationery Office, The, 2020.

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3

Agency, Great Britain: Highways. Design manual for roads and Bridges : Vol. 3 : Highway structures : inspection and maintenance, Section 4 : Assessment, Part 20: Use of compressive membrane action in bridge Decks. Stationery Office, The, 2007.

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4

England, Highways. Design Manual for Roads and Bridges : Vol. 3 : Highways Structures : Inspection and Maintenance, Section 4 : Assessment, Part 20: CD 360 Use of Compressive Membrane Action in Bridge Decks. Stationery Office, The, 2018.

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5

England, Highways. Design Manual for Roads and Bridges : Vol. 3 : Highways Structures : Inspection and Maintenance, Section 4 : Assessment, Part 20: CD 360 Use of Compressive Membrane Action in Bridge Decks. Stationery Office, The, 2018.

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Частини книг з теми "Compressive membrane action"

1

Belletti, B., F. Vitulli, and J. Walraven. "Compressive membrane action in confined RC and SFRC circular slabs." In Computational Modelling of Concrete Structures, 807–18. CRC Press, 2014. http://dx.doi.org/10.1201/b16645-92.

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2

Hart, Andrew. "Pathophysiology." In Oxford Textbook of Plastic and Reconstructive Surgery, 293–94. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780199682874.003.0044.

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Compression neuropathy is the commonest form of peripheral nerve injury and refers to the symptoms and clinicopathological findings that arise when a peripheral nerve is subjected to acute or chronic external compression or impingement of sufficient magnitude to impair its microcirculation. As aerobic glycolysis fails, membrane potential regulation is impaired, and action potential transmission fails. The differential susceptibility of the various fibre types, which subserve different functions, results in a typical progression of symptoms from impaired fine touch and proprioception, through paraesthesia, to poorly localized pain. If compression persists, then secondary intraneural and vascular anatomical changes establish a downward spiral of worsening intraneural oedema and fibrosis, axonotmesis, and denervation atrophy of target muscles. The condition becomes refractory to decompression. The impact on the patient depends upon the severity of neuropathy, and the nerve affected. A small number of anatomical sites particularly predispose to compression (e.g. the carpal tunnel), resulting in the common clinical syndromes.

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Тези доповідей конференцій з теми "Compressive membrane action"

1

Genikomsou, Aikaterini, and Maria Anna Polak. "Finite element investigation of the compressive membrane action effect on concrete slabs." In IABSE Symposium, Vancouver 2017: Engineering the Future. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2017. http://dx.doi.org/10.2749/vancouver.2017.1082.

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2

Lantsoght, Eva O. L., Cor van der Veen, Rutger Koekkoek, and Henk Sliedrecht. "Capacity of prestressed concrete bridge decks under fatigue loading." In IABSE Congress, Ghent 2021: Structural Engineering for Future Societal Needs. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/ghent.2021.0313.

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<p>In The Netherlands, existing slab-between-girder bridges with prestressed girders and thin transversely prestressed concrete decks require assessment. The punching capacity was studied in a previous series of experiments, showing a higher capacity thanks to compressive membrane action in the deck. Then, concerns were raised with regard to fatigue loading. To address this, two series of large-scale experiments were carried out, varying the number of loads (single wheel print versus double wheel print), the loading sequence (constant amplitude versus variable amplitude, and different loading sequences for variable amplitude), and the distance between the prestressing ducts. An S-N curve is developed for the assessment of slab-between-girder bridges. The experiments showed that compressive membrane actions enhances the capacity of thin transversely prestressed decks subjected to fatigue loading.</p>

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3

Amir, Sana, Cor van der Veen, Joost C. Walraven, and Ane de Boer. "Bearing capacity of transversely prestressed concrete deck slabs." In IABSE Conference, Copenhagen 2018: Engineering the Past, to Meet the Needs of the Future. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2018. http://dx.doi.org/10.2749/copenhagen.2018.298.

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All over the world, the safety of old structures is a question that has become increasingly important with the passage of time. In the Netherlands, there are a large number of thin, transversely prestressed concrete bridge decks, cast in-situ between the flanges of long prestressed concrete girders. These bridges date back to the 60’s and 70’s of the last century and are found to be critical in shear when analyzed using the recently implemented EN 1992-1-1:2005 (CEN 2005). With the on-going economic recession, it is an astute approach to check if such bridges can still be used for a few more decades, provided they are safe and reliable against the modern traffic loads. The results could then be applied on a wider range of structures, especially in developing countries facing economic constraints. Therefore, a prototype bridge was selected and experimental, numerical and theoretical approach was used to investigate its bearing capacity, loaded by a single and double wheelprint loadcase. Nineteen tests on a 1:2 scale model of the bridge were carried out in the laboratory. Later the bridge was modelled as a 3D solid, 1:2 scale using the finite element software TNO DIANA 9.4.4 and several nonlinear analyses were carried out. Furthermore, a theoretical analysis, using the bearing capacity obtained from the fib Model code 2010 punching shear provisions (based on the Critical Shear Crack Theory for prestressed slabs), and the experimental and numerical ultimate capacities, showed comparable results. A coefficient of variation of 11% and 9% was obtained when the experimental and the finite element analysis punching loads were compared with the theoretical results involving compressive membrane action, respectively. This led to the conclusion that the existing transversely prestressed concrete bridge decks still have sufficient residual bearing (punching shear) capacity and considerable saving in cost can be made if compressive membrane action is considered in the analysis.

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4

Venkatesan, Vidyashankar, and Nilay Mukherjee. "Finite Element Model of a Cell Incorporating Cell Membrane, Cytoskeletal Structure and Intracellular Fluid Pressure." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32667.

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Compressive loading is intrinsic to certain tissues in our body like articular cartilage and bone (1). In situ experiments in cartilage suggest that chondrocytes can undergo significant deformation due to compressive loading on the tissue (2). In situ and isolated cell experiments have concluded that cells are quite resilient to compressive loading, aspiration etc. and exhibit a moduli in the range of 0.6 to 2 kPa (3). However, few studies have attempted to understand the compressive behavior of cells in terms of its structural components. The structural components of a cell consist of a membrane and a dense network of at least three elements (actin, microtubules and intermediate filaments). Using finite element analysis techniques we wanted to explore the role of these structural components in determining the ability of the cell to withstand compression.

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5

Guijarro, E., J. M. Ferrero, and T. Diez-Caballero. "Action potential model based on the compression of the cell membrane." In Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1988. http://dx.doi.org/10.1109/iembs.1988.95275.

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6

Share, Dylan, Lakshmi Krishnan, David Lesperence, Daniel Walczyk, and Raymond Puffer. "Cold Pressing of Membrane Electrode Assemblies for High-Temperature PEM Fuel Cells." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33230.

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With the current economic and environmental situation, the development of affordable and clean energy sources is receiving much attention. One leading area of promise is PEM fuel cells. Presently, manufacture of high temperature Polybenzimidizole (PBI) based PEM Membrane Electrode Assemblies (MEAs) is usually performed by sealing in a thermal press. A typical sealing process requires heated tooling to press electrode-subgasket assemblies into a sol-gel PBI membrane. MEAs designed for transportation purposes have a large active area that requires expensive heated tooling, which in turn requires significant power to operate. A previous Design of Experiments (DoE) and analysis revealed that sealing temperature is a statistically insignificant sealing parameter with respect to MEA performance. To further investigate the effects of sealing temperature on MEA performance in hopes of reducing manufacturing costs, an additional DoE was performed in which MEAs were manufactured with the tooling at room temperature. This paper examines the effect of thermal sealing process parameters, namely: (1) sealing temperature; (2) percent compression, and; (3) seal time on the fuel cell performance. MEAs were manufactured using three different thickness membranes with these input process parameters. Polarization behavior during single cell operation, internal cell resistance and catalyst utilization were analyzed as performance parameters. This data is compared to MEAs made with traditional heated tooling. The analysis reveals the insignificance of sealing temperature on the initial performance of the MEA.

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7

Fan, Tai-Hsi, and Andrei G. Fedorov. "Electrohydrodynamics and Surface Force Analysis in AFM Imaging of a Charged, Deformable Biological Membrane in a Dilute Electrolyte Solution." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45152.

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Surface forces arising in AFM imaging of a deformable, negatively charged biological membrane in an electrolyte solution are investigated in the limit of continuous electrohydrodynamics. Specifically, we extend our previous analysis [1] of purely hydrodynamic interactions between an AFM tip and the elastic cell membrane by accounting for electric double-layer forces under the assumption of a dilute electrolyte solution and local electrochemical equilibrium. The solution of the problem is obtained by integrating the quasisteady, electrically-forced Stokes equation for the electrohydrodynamic field, the linearized Poisson-Boltzmann equation for the electrostatic field in the electrolyte inside and outside of the cell, and the Laplace equation for the electrostatic field within a dielectric AFM tip. The Helfrich and Zhongcan’s equation for an equilibrium shape of the cell membrane is employed as a quasi-steady, nonlinear boundary condition linking the stress fields on both sides of the cell membrane augmented by the local membrane incompressibility condition in order to find the local tension/compression force acting on the membrane. For the first time, an integrated framework for the dynamic coupling of the membrane double-layer effects and the AFM tip-electrolyte-membrane motion is established that allows for characterizing of the local electrolyte flow field, the electrostatic field, the elastic deformation of the membrane, and the electrohydrodynamic surface force acting on the AFM tip in great detail. The results of the analysis provide information on the motion of the membrane and the surface forces induced by both an electrolyte motion and the Maxwell stresses resulting from the charge double-layer screening effect for a full cycle motion of the AFM tip in a non-contact mode imaging of the cell membrane.

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8

Rizzello, Gianluca, Micah Hodgins, David Naso, Alexander York, and Stefan Seelecke. "Dynamic Electromechanical Modeling of a Spring-Biased Dielectric Electroactive Polymer Actuator System." In ASME 2014 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/smasis2014-7617.

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This paper presents a dynamic electromechanical model for an actuator system based on a Dielectric Electro-Active Polymer (DEAP) membrane biased with a linear spring. The motion is generated by the deformation of the membrane caused by the electrostatic compressive force between two compliant electrodes applied on the surface of the polymer. A mass and a linear spring are used to pre-load the membrane, allowing stroke in the out-of-plane direction. The development of mathematical models which accurately describe the nonlinear system dynamics is a fundamental step in order to design model-based, high-precision position control algorithms. In particular, knowledge of the nonlinear electrical dynamics of the actuator driving circuit can be exploited during the control system design in order to achieve desirable features, such as self-sensing or control energy minimization. This work proposes an electromechanical physical model of the DEAP actuator system. By means of numerous experiments, it is shown that the model can be used to predict the current by measuring deformation and voltage (electrical dynamics), as well as predicting deformation and current by measuring the voltage (electromechanical dynamics).

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9

Olesen, Anders C., Torsten Berning, and So̸ren Knudsen Kær. "The Effect of Inhomogeneous Compression on Water Transport in the Cathode of a PEM Fuel Cell." In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54925.

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Анотація:

A three-dimensional, multi-component, two-fluid model developed in the commercial CFD package CFX 13 (ANSYS inc.), is used to investigate the effect of porous media compression on transport phenomenon of a PEM Fuel cell (PEMFC). The PEMFC model only consist of the cathode channel, gas diffusion layer, micro-porous layer and catalyst layer, excluding the membrane and anode. In the porous media liquid water transport is described by the capillary pressure gradient, momentum loss via the Darcy-Forchheimer equation and mass transfer between phases by a non-equilibrium phase change model. Furthermore, the presence of irreducible liquid water is taken into account. In order to account for compression, porous media morphology variations are specified based on the GDL throughplane strain and intrusion which are stated as a function of compression. These morphology variations affect gas and liquid water transport, and hence liquid water distribution and the risk of blocking active sites. Hence, water transport is studied under GDL compression, in order to investigate the qualitative effects. Two simulation cases are compared; one with and one without compression.

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10

Srinivasan, Jayendran, Vincent Kish, Vidyashankar Venkatesan, Sydha Salihu, Madhavi Ayyalasomayajula, and Nilay Mukherjee. "Material Properties of Cells Can Be Determined From Compression Experiments of Cell-Gel Constructs." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32664.

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Анотація:

Mechanical loading has been implicated in regulating cellular behavior which in turn affect tissue development, growth, maintenance and regeneration. The structural components of the cell (cell membrane, transmembrane proteins such as integrins and at least three cytoskeletal networks of actin, microtubules and intermediate filaments) are involved in converting the mechanical loading into biochemical signals which then affect cellular behavior (1). Further, cells are known to alter their cytoskeletal structure during cell division (2), differentiation (3), pathology (4) and in response to mechanical loading (5). These changes will probably be reflected in gross material properties of the cell, such as modulus of elasticity. In this work, we describe a system to determine the modulus of elasticity of cells when they are embedded in agarose gel and subjected to compressive loading.

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