Статті в журналах: "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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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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11

Cantone, Raffaele, Beatrice Belletti, Luca Manelli, and Aurelio Muttoni. "Compressive Membrane Action Effects on Punching Strength of Flat RC Slabs." Key Engineering Materials 711 (September 2016): 698–705. http://dx.doi.org/10.4028/www.scientific.net/kem.711.698.

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The design of reinforced concrete flat slabs in practice can be governed at failure by punching shear close to concentrated loads or columns. Punching shear resistance formulations provided by codes are calibrated on the basis of experimental tests on isolated slabs supported on columns in axisymmetric conditions. Nevertheless, the behavior of flat slabs can be different than isolated specimens due to the potentially beneficial contributions of moment redistributions and compressive membrane actions. Accounting for the significance of these effects, nonlinear finite element analyses are performed with the crack model PARC_CL implemented in Abaqus. This paper aims to investigate a series of punching shear tests on slabs with and without shear reinforcement, different reinforcement ratios and loading conditions accounting for the potential contribution to the enhancement of the punching strength due to compressive membrane action (CMA). The numerical results with a multi – layered shell modeling are then post – processed adopting the failure criterion of the Critical Shear Crack Theory (CSCT). The results pointed out the significant outcomes and differences between standard specimens and actual members showing how the current codes of practice may underestimate the punching capacity.

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12

Collings, David, and Juan Sagaseta. "A review of arching and compressive membrane action in concrete bridges." Proceedings of the Institution of Civil Engineers - Bridge Engineering 169, no. 4 (December 2016): 271–84. http://dx.doi.org/10.1680/bren.14.00039.

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13

Peel-Cross, J., G. I. B. Rankin, S. G. Gilbert, and A. E. Long. "Compressive membrane action in composite floor slabs in the Cardington LBTF." Proceedings of the Institution of Civil Engineers - Structures and Buildings 146, no. 2 (May 2001): 217–26. http://dx.doi.org/10.1680/stbu.2001.146.2.217.

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14

Eyre, J. R., and K. O. Kemp. "In-plane stiffness of reinforced concrete slabs under compressive membrane action." Magazine of Concrete Research 46, no. 166 (March 1994): 67–77. http://dx.doi.org/10.1680/macr.1994.46.166.67.

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15

Zeng, Yihua, Wouter Botte, and Robby Caspeele. "Reliability analysis of FRP strengthened RC beams considering compressive membrane action." Construction and Building Materials 169 (April 2018): 473–88. http://dx.doi.org/10.1016/j.conbuildmat.2018.03.019.

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16

Keyvani, Leila, Mehrdad Sasani, and Yaser Mirzaei. "Compressive membrane action in progressive collapse resistance of RC flat plates." Engineering Structures 59 (February 2014): 554–64. http://dx.doi.org/10.1016/j.engstruct.2013.10.040.

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17

Lantsoght, Eva O. L., Rutger Koekkoek, Cor van der Veen, and Henk Sliedrecht. "Fatigue Assessment of Prestressed Concrete Slab-Between-Girder Bridges." Applied Sciences 9, no. 11 (June 5, 2019): 2312. http://dx.doi.org/10.3390/app9112312.

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In the Netherlands, the assessment of existing prestressed concrete slab-between-girder bridges has revealed that the thin, transversely prestressed slabs may be critical for static and fatigue punching when evaluated using the recently introduced Eurocodes. On the other hand, compressive membrane action increases the capacity of these slabs, and it changes the failure mode from bending to punching shear. To improve the assessment of the existing prestressed slab-between-girder bridges in the Netherlands, two 1:2 scale models of an existing bridge, i.e., the Van Brienenoord Bridge, were built in the laboratory and tested monotonically, as well as under cycles of loading. The result of these experiments revealed: (1) the static strength of the decks, which showed that compressive membrane action significantly enhanced the punching capacity, and (2) the Wöhler curve of the decks, showed that the compressive membrane action remains under fatigue loading. The experimental results could then be used in the assessment of the most critical existing slab-between-girder bridges. The outcome was that the bridge had sufficient punching capacity for static and fatigue loads and, therefore, the existing slab-between-girder bridges in the Netherlands fulfilled the code requirements for static and fatigue punching.

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18

Marshe, Sylvanus, and Mark F. Green. "Punching behaviour of composite bridge decks transversely prestressed with carbon fibre reinforced polymer tendons." Canadian Journal of Civil Engineering 26, no. 5 (October 1, 1999): 618–30. http://dx.doi.org/10.1139/l99-027.

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Composite bridge decks under concentrated wheel loading develop compressive membrane action that tends to increase significantly the strength of the deck slab. Transverse prestressing of the deck slab can improve the compressive membrane action and allow a reduction in the slab thickness. With a reduced thickness, however, durability is a concern with steel prestressing tendons. By using fibre reinforced polymer prestressing tendons, the durability of the bridge deck slab can be improved. This paper describes an experimental investigation to study the punching behaviour of composite bridge decks transversely prestressed with carbon fibre reinforced polymer (CFRP) tendons. Six panels of a 1/4.04-scale model of a simply supported composite bridge deck are tested under a static concentrated wheel loading. The results are compared to those from a previous similar study using steel prestressing tendons. It is shown that it is feasible to use CFRP tendons to transversely prestress composite bridge decks, and that the CFRP prestressed bridge deck shows better overall structural performance than the steel prestressed deck. The lack of plasticity of the CFRP tendons is not a concern in this application.Key words: composite bridge deck, concrete, compressive membrane action, punching shear, prestressing, advanced composite material (ACM), fibre reinforced polymer (FRP).

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19

Zhu, Ying-Jie, Jia-Ji Wang, Xin Nie, Xue-Bei Pan, and Jian-Sheng Fan. "Structural performance of slabs in composite box girder considering compressive membrane action." Engineering Structures 212 (June 2020): 110457. http://dx.doi.org/10.1016/j.engstruct.2020.110457.

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20

Chen, Wanxiang, Lisheng Luo, Zhikun Guo, and Yingjie Wang. "Load-Carrying Capacities of Fully Clamped RC Slab Accompanying Compressive-Tensile Membrane Actions: A Theoretical Approach." International Journal of Structural Stability and Dynamics 20, no. 08 (July 2020): 2050094. http://dx.doi.org/10.1142/s0219455420500947.

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Fully clamped reinforced concrete (RC) slab is a common structural component possessing better load-carrying capacity over simply supported slab. Currently, typical yield line theory is a popular approach to estimate the bearing capacity of fully clamped RC slab, although it would greatly underestimate the actual ultimate resistance. This paper is devoted to enriching the knowledge of membrane action and its contribution to the load-carrying capacity of the clamped slab. The resistance trajectory of fully clamped RC slab from loading to failure undergoes three phases: the ascending branch raised by outward movement prevention, the descending branch due to crushed concrete and the re-ascending branch caused by reinforcement strain. Applied load–deflection curves of RC slab accompanying compressive-membrane actions are achieved according to the bending theory of normal cross-section. The reserve capacities accompanying tensile-membrane actions in the condition of large deformations are further derived. The whole load–deflection curves that considered compressive-tensile membrane effects are finally presented, where the mid-span displacements are revised by the deflection equations and the softening coefficient of flexural rigidity. It is indicated that the load–deflection relationships of fully clamped RC slabs can be reasonably depicted by taking compressive-tensile membrane effects into account, which are fairly different from yield line approaches. Comparative analysis shows that analytical results are in good agreement with experimental data reported by Park et al. and illustrates that the proposed model is capable of predicting the bearing capacity of fully clamped RC slab with very good accuracy.

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21

Wang, Qing Xiang, Gang Wang, and Zhong Jun Li. "Experiment Study on Compressive Membrane Action of Slab Strips Restrained by Shear Walls." Key Engineering Materials 417-418 (October 2009): 805–8. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.805.

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Subjecting to the compressive membrane action (CMA), the ultimate load capacity of the reinforced concrete (RC) slab with lateral restraint would be improved obviously. Test of 12 one-way slab specimens restrained by shear-walls was carried out to investigate the properties of the slab strips’ compressive membrane action. The reduced-size specimens were designed to keep the ratios of shear-walls’ restraint stiffness to slab strips’ flexural stiffness unchanged. One horizontal testing instrument was first used to record the development of the slabs’ lateral restraint forces. The ultimate loads of slab strips with certain lateral restraint stiffness gave an average 38.3% rise from the calculations of upper-bound method. Though the increment of slab’s ultimate load was due to the additional moment formed by the lateral restraint force, the results showed that the peak of lateral force lagged of the slab strips’ ultimate load, which was different from the previous hypothesis. Various parameters which affect the development of CMA were also investigated, such as the shear-wall’s thickness, axial load on the walls, the slab strips’ span-height ratio and reinforcement percentage.

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22

Ahmed Mohammed Wagieallah, Rammah, and Mohammed Tagelsir Mustafa Abdelsalam. "Modelling of Compressive Membrane Action for Fully-laterally Restrained Two-way R.C Slabs." FES Journal of Engineering Sciences 9, no. 1 (February 22, 2021): 30–36. http://dx.doi.org/10.52981/fjes.v9i1.654.

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Current design codes do not account for the effect of compressive membrane action (CMA) in reinforced concrete slabs, which can increase their capacities, and hence yields more economical design. This paper studies the influence of CMA for laterally restrained two-way slabs. The main aim is to develop a simple model to reasonably predict the enhancement in load-carrying capacity due to CMA for laterally restraint two-way RC slabs under uniformly distributed loading. In order to meet this aim, a numerical technique was used. The developed model had been validated against relevant experimental studies from literature. The parameters influencing the CMA were identified. These included the reinforcement ratio and span-thickness ratio. It was shown that the CMA decreases by increasing the percentage of reinforcement and span-to-thickness ratio. After that, a numerical model for evaluating the CMA for laterally restrained two-way slabs has been proposed. The model was examined against 43 slab specimens from literature. The correlation achieved was satisfactory, despite the wide range of variables involved in tests. The mean ratio of the experimental to the predicted ultimate load was 1.00, and the coefficient of variance (COV) equal to 25%.

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23

Tharmarajah, Gobithas, Su Taylor, and Desmond Robinson. "Experimental and Numerical Investigation of Compressive Membrane Action in GFRP-Reinforced Concrete Slabs." Polymers 15, no. 5 (February 28, 2023): 1230. http://dx.doi.org/10.3390/polym15051230.

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Experimental and numerical analyses of eight in-plane restrained slabs (1425 mm (length) × 475 mm (width) × 150 mm (thickness)) reinforced with glass fiber-reinforced polymer (GFRP) bars are reported in this paper. The test slabs were installed into a rig, that provided 855 kN/mm in-plane stiffness and rotational stiffness. The effective depths of the reinforcement in the slabs varied from 75 mm to 150 mm, and the amount of reinforcement changed from 0 to 1.2% with 8, 12, and 16 mm bar diameters. A comparison of the service and ultimate limit state behavior of the tested one-way spanning slabs shows that a different design approach is necessary for GFRP-reinforced in-plane restrained slabs that demonstrate compressive membrane action behavior. Design codes based on yield line theory, which considers simply supported and rotationally restrained slabs, are not sufficient to predict the ultimate limit state behavior of restrained GFRP-reinforced slabs. Tests reported a higher failure load for GFRP-reinforced slabs by a factor of 2, which was further validated by numerical models. The experimental investigation was validated by a numerical analysis, and the acceptability of the model was further confirmed by consistent results obtained by analyzing in-plane restrained slab data from the literature.

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24

Li, Chen, and Fang Qin. "Theoretical and Numerical Analysis on Membrane Effects of RC Slabs." Advanced Materials Research 255-260 (May 2011): 1900–1905. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.1900.

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When a RC structure is laterally restrained, the load resistance is enhanced due to the membrane effects. A simplified membrane action theory was proposed by modifying the Maximum Membrane Force Design Method (MMFM) to predict the resistance-deflection curves of restrained slab RC structures, in which the total strain plastic theory and strain rate plastic theory were combined and a serial of explicit formulae were derived. A better agreement was observed between the test data and the analytical results predicted by the proposed theoretical method, comparing with MMFM and numerical results conducted by ABAQUS. It is demonstrated that the proposed theory is validated and the steel bar at compressive zone has definite influence on the load carrying capacity, and cannot be neglected in the case of high compressive reinforcement ratio.

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25

Kuang, J. S., and C. T. Morley. "A plasticity model for punching shear of laterally restrained slabs with compressive membrane action." International Journal of Mechanical Sciences 35, no. 5 (May 1993): 371–85. http://dx.doi.org/10.1016/0020-7403(93)90009-j.

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26

Morley, C. T. "A plasticity model for punching shear of laterally restrained slabs with compressive membrane action." International Journal of Mechanical Sciences 35, no. 10 (October 1993): 889. http://dx.doi.org/10.1016/0020-7403(93)90047-x.

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27

Zhu, Ying-Jie, Yue Yang, Jia-Ji Wang, and Li-Yan Xu. "Novel design method for reinforced concrete decks in composite girders considering compressive membrane action." Engineering Structures 229 (February 2021): 111558. http://dx.doi.org/10.1016/j.engstruct.2020.111558.

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28

Einpaul, Jürgen, Miguel Fernández Ruiz, and Aurelio Muttoni. "Influence of moment redistribution and compressive membrane action on punching strength of flat slabs." Engineering Structures 86 (March 2015): 43–57. http://dx.doi.org/10.1016/j.engstruct.2014.12.032.

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29

Belletti, Beatrice, Joost C. Walraven, and Francesco Trapani. "Evaluation of compressive membrane action effects on punching shear resistance of reinforced concrete slabs." Engineering Structures 95 (July 2015): 25–39. http://dx.doi.org/10.1016/j.engstruct.2015.03.043.

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30

Genikomsou, Aikaterini S., and Maria Anna Polak. "3D finite element investigation of the compressive membrane action effect in reinforced concrete flat slabs." Engineering Structures 136 (April 2017): 233–44. http://dx.doi.org/10.1016/j.engstruct.2017.01.024.

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31

Buckle, I. G., A. R. Dickson, and M. H. Phillips. "Ultimate strength of three reinforced concrete highway bridges." Canadian Journal of Civil Engineering 12, no. 1 (March 1, 1985): 63–72. http://dx.doi.org/10.1139/l85-007.

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The destructive testing of three reinforced concrete highway bridges, recently made redundant by road realignment, is summarized. The procedure used to test the bridges to ultimate conditions is described and load capacities of about 20 times class 1 axle loads are reported for all structures. Analyses based on conventional ultimate strength theory can account for only two-thirds of these ultimate loads and then only if second order effects are included. A nonlinear finite element computer program has been developed and used to analyze one of these structures. Excellent prediction of the ultimate load is made by the program. It is therefore suggested that compressive membrane action, which is automatically modelled in the finite element solution, plays a significant role in the enhancement of load capacity.The paper concludes that a more sophisticated approach to the assessment of bridge load capacity is necessary if realistic estimates of actual strength are to be made. Limited experience with a nonlinear finite element program suggests one such approach. If used with care, some relief to the bridge replacement program can be expected. Key words: highway bridges, ultimate load capacity, finite element analysis, reinforced concrete, field testing, compressive membrane action.

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32

Seraji, Mahmood, W. H. Wan Badaruzzaman, and S. A. Osman. "Experimental Study on the Compressive Membrane Action in Profiled Steel Sheet Dry Board (PSSDB) Floor System." International Journal on Advanced Science, Engineering and Information Technology 2, no. 2 (2012): 159. http://dx.doi.org/10.18517/ijaseit.2.2.176.

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Dat, Pham Xuan, Trieska Yokhebed Wahyudi, and Do Kim Anh. "Analytical model for predicting membrane actions in RC beam-slab structures subjected to penultimate-internal column loss scenarios." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 12, no. 3 (April 30, 2018): 10–22. http://dx.doi.org/10.31814/stce.nuce2018-12(3)-02.

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The potential for progressive collapse of RC buildings can be estimated by column loss scenarios. The loss of either internal or external penultimate columns is among the most critical scenarios since the beam-slab substructures associated with the removed column becomes laterally unrestrained with two discontinuous edges. At large deformations, membrane behaviour of the associated slabs, consisting of a compressive ring of concrete around its perimeter and tensile membrane action in the central region, represents an important line of defence against progressive collapse. The reserve capacity can be used to sustain amplified gravity loads and to mitigate the progressive collapse of building structures. In this paper, based on experimental observation of 1/4 scaled tests together with investigation of previous research works, an analytical model is proposed to predict the load-carrying capacity of beam-slab structures at large deformations. Comparison with the test results shows that the analytical model gives a good estimation of the overall load-carrying capacity of the RC slabs by membrane actions. Article history: Received 15 March 2018, Revised 28 March 2018, Accepted 27 April 2018

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Ouyang, Hui, Beth Galle, Jianming Li, Eric Nauman, and Riyi Shi. "Critical roles of decompression in functional recovery of ex vivo spinal cord white matter." Journal of Neurosurgery: Spine 10, no. 2 (February 2009): 161–70. http://dx.doi.org/10.3171/2008.10.spi08495.

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Object The correlations between functional deficits, the magnitude of compression, and the role of sustained compression during traumatic spinal cord injury remain largely unknown. Thus, the functional outcome of this type of injury with or without surgical intervention is rather unpredictable. To elucidate how severity and duration of compression affect cord function, the authors have developed a method to study electrophysiological characteristics and axonal membrane damage in white matter from guinea pig spinal cord. Methods Ventral white matter strips isolated from adult guinea pigs were compressed by a compression rod at a level of either 60 or 80% and held briefly, for 30 minutes, or for 60 minutes. In half the experimental groups, a decompression phase consisting of probe withdrawal and 30 minutes of recovery was also applied. For all cord samples, functional response was continuously monitored through compound action potential (CAP) recording. In addition, axonal membrane damage was assessed by a horseradish peroxidase (HRP) exclusion assay. Results After 30 minutes of sustained compression at levels of 60 or 80%, a spinal cord decompression procedure caused a significant CAP recovery, with specimens reaching 97.5 ± 6.84% (p < 0.05) and 56.2 ± 6.14% (p < 0.05) of preinjury amplitude, respectively. After 60 minutes of compression, the amount of CAP recovery following the decompression stage was only 65.5 ± 9.33% for 60% compression (p < 0.05) and 29.8 ± 6.31% for 80% compression (p < 0.05). Unlike the CAP response, HRP uptake did not increase during sustained compression, and the data showed that HRP staining was primarily time dependent. Conclusions The degree of axonal membrane damage is not exacerbated during sustained compression. However, the electrical conductivity of the cord white matter weakens throughout the duration of compression. Therefore, decompression is a viable procedure for preservation of neurological function following compressive injury.

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35

CHEN, LI, QIN FANG, ZHIKUN GUO, and JINCHUN LIU. "AN IMPROVED ANALYTICAL METHOD FOR RESTRAINED RC STRUCTURES SUBJECTED TO STATIC AND DYNAMIC LOADS." International Journal of Structural Stability and Dynamics 14, no. 01 (December 17, 2013): 1350052. http://dx.doi.org/10.1142/s0219455413500521.

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Once a RC structure is laterally restrained, both the static and dynamic load resistances will be enhanced due to the membrane action. Despite this known advantage, the apparent lack of systemic and efficient methods of analysis poses a drawback in the design and assessment of blast-resistant RC structures. First, a simplified membrane action theory was presented by modifying the maximum membrane force design method (MMFM) for predicting the total static resistance-deflection curves of restrained beam-slab RC structures. Second, a series of constrained beams were tested to validate the new theory, for which better agreement was observed between the test data, the results predicted by the proposed theory and those by MMFM. The results show that the static load carrying capacity and membrane force increase with increasing restraint stiffness, and the smaller the reinforcement ratio is, the larger the load carrying capacity increases. Third, based on the improved compressive static membrane action theory, a new analytical method was developed to investigate the dynamic responses of restrained RC structures subjected to blast loads, using an equivalent single degree of freedom system that combines the three-parameter elasto-viscoplastic rate-sensitive material model with the proposed static theory. Good agreement is observed between the test data and the analytical results. Finally, it is demonstrated that the dynamic resistance capacity increases with increasing load rate and restraint stiffness and with decreasing tensile reinforcement ratio, but the larger the dynamic resistance is, the larger the plastic deformation of the structure.

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36

Zhu, Ying-Jie, Meng Zhou, Jian-Min Zhu, and Xin Nie. "Analytical models for load capacities of variable thickness reinforced concrete slabs considering compressive membrane action and boundary effects." Engineering Structures 246 (November 2021): 113067. http://dx.doi.org/10.1016/j.engstruct.2021.113067.

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37

Ahmed, Mohd, Saeed AlQadhi, Saleh Alsulamy, Saiful Islam, Roohul A. Khan, and Mohd Danish. "Development of Self-Cured Sustainable Concrete Using Local Water-Entrainment Aggregates of Vesicular Basalt." Sustainability 13, no. 12 (June 15, 2021): 6756. http://dx.doi.org/10.3390/su13126756.

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The environmental and economic concerns pertaining to the construction industry have necessitated the development of sustainable concrete. Durability and strength are the two primary properties which determine the sustainability of concrete. This study evaluated the performance of self-cured concrete produced from local vesicular basalt porous aggregates. The durability indicators, porosity, permeability and pore size of the hardened concrete, were obtained from the water sorptivity (water permeability under capillary action) test, the water permeability under pressure action test and the Brunauer–Emmett–Teller (BET) surface area test and strength was evaluated in terms of compressive strength of concrete. The concrete specimens were produced with 10% porous vesicular basalt aggregate in replacement of coarse aggregate. The concrete specimens were tested at 3, 7 and 28 days. The self-curing effect on concrete strength was evaluated against water, air and membrane cured specimens, at surface/volume ratio of 26.4/40 and w/c ratio of 0.35/0.5. A 20% decrease in sorptivity coefficient, 10% increase in solid surface area and about 10% increase in compressive strength of the self-cured concrete was observed over the conventionally cured concrete. The study concludes that the addition of water-entrainment aggregates to concrete reduces water permeability, results in a finer pore structure of concrete and increases the quality and durability of concrete.

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38

Govender, Sendhil, and James G. Colebatch. "Location and phase effects for ocular and cervical vestibular-evoked myogenic potentials evoked by bone-conducted stimuli at midline skull sites." Journal of Neurophysiology 119, no. 3 (March 1, 2018): 1045–56. http://dx.doi.org/10.1152/jn.00695.2017.

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Our object was to investigate the effect of location and phase on the properties of oVEMPs and cVEMPs evoked by two bone conducted (BC) stimuli, 500 Hz and an impulsive stimulus for midline skull sites from Nz to Iz, in normal volunteers. Compressive and rarefactive onset phases were used and the induced linear and rotational accelerations measured. We confirmed our previous finding of marked changes in the polarity of oVEMPs with location. For cVEMPs using the 500Hz stimulus there were few changes with location or phase, but the impulsive stimulus showed clear phase-related changes at several locations, with the shortest latencies occurring with compressive stimuli at AFz and Fz and the largest amplitudes at Iz. For oVEMPs, both stimuli showed clear effects of phase, with the shortest latencies with compressive stimuli at AFz and Fz and with the largest negativity at Oz or Iz. Whereas the effectiveness at Iz is consistent with a role in the linear VOR, the inversion of polarity and shorter latency around AFz and Fz is not and could not be explained by changes in acceleration of the head. The latency for BC 500Hz oVEMPs for AFz was the same as that for air-conducted (AC) stimuli. We suggest that whereas BC stimuli at most sites work through displacement of the otolith membrane, BC oVEMPs evoked at AFz and Fz may work through a direct action on utricular hair cells. Our findings have implications for clinical testing of VEMPs using midline BC stimuli. NEW & NOTEWORTHY We investigated VEMPs evoked from multiple midline skull sites. Large oVEMP responses were obtained with compressive stimuli at Iz, consistent with a role in the linear VOR, but we also showed inversion of polarity and the shortest latency for stimuli given at AFz and Fz. We propose that BC stimuli given at AFz and Fz may have a direct effect on otolith hair cells, whereas at other sites they work through displacement of the otolith membrane.

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39

Zheng, Yu, and Yun Feng Pan. "Prediction Methods for Ultimate Strengths in GFRP Reinforced Concrete Bridge Deck Slabs." Advanced Materials Research 163-167 (December 2010): 1139–42. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1139.

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The corrosion of reinforcement embedded in concrete bridge deck slabs has been the cause of major deterioration and of high costs in repair and maintenance. Fibre reinforced polymers (FRP) exhibit high durability in combination with high strength and light weight. The majority of research with FRP bars for reinforcing concrete has been on simply supported beams and slabs where the low value of elasticity of FRP has meant that the service behaviour has been critical. These differences have been attributed to the low value of elasticity of many FRPs compared to steel. However, laterally restrained slabs, such as those in bridge deck slabs, exhibit arching action or compressive membrane action (CMA), which has a beneficial influence on the service behaviour such as the deflection. Based on the previous research on CMA in steel reinforced concrete bridge deck slabs, a modified theoretical method were established according to the material properties of GFRP reinforcement. The proposed prediction method showed a good collection of some reported GFRP reinforced slabs experimental tests.

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40

Clarke, Margaret, Annette Müller-Taubenberger, Kurt I. Anderson, Ulrike Engel, and Günther Gerisch. "Mechanically Induced Actin-mediated Rocketing of Phagosomes." Molecular Biology of the Cell 17, no. 11 (November 2006): 4866–75. http://dx.doi.org/10.1091/mbc.e06-04-0365.

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Actin polymerization can be induced in Dictyostelium by compressing the cells to bring phagosomes filled with large particles into contact with the plasma membrane. Asymmetric actin assembly results in rocketing movement of the phagosomes. We show that the compression-induced assembly of actin at the cytoplasmic face of the plasma membrane involves the Arp2/3 complex. We also identify two other proteins associated with the mechanically induced actin assembly. The class I myosin MyoB accumulates at the plasma membrane–phagosome interface early during the initiation of the response, and coronin is recruited as the actin filaments are disassembling. The forces generated by rocketing phagosomes are sufficient to push the entire microtubule apparatus forward and to dislocate the nucleus.

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41

Kromoser, Benjamin, Thomas Pachner, Chengcheng Tang, Johann Kollegger, and Helmut Pottmann. "Form Finding of Shell Bridges Using the Pneumatic Forming of Hardened Concrete Construction Principle." Advances in Civil Engineering 2018 (November 29, 2018): 1–14. http://dx.doi.org/10.1155/2018/6309460.

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Concrete shells are fascinating structures. Even thin shells can span over large areas without requiring any columns. If a form-defining load case exists, the shape of the shell can be designed to ensure that the forces in the structure are transferred primarily by the membrane action, which leads to an even distribution of the stresses across the shell surface. Concrete as a material, characterized by high compressive strength and low tensile strength, can be used with a very high degree of utilization. A fundamental problem with building concrete shells is the high effort required for the production of the complicated formwork. A new construction principle called Pneumatic Forming of Hardened Concrete (PFHC) was invented at TU Wien and requires no traditional formwork or falsework during the construction process. An air cushion is used to lift a flat hardened concrete plate, and at the same time, additional post-tensioning cables are tightened to support the transformation of the flat plate into a double-curved shell. One possible application of PFHC is the construction of shell bridges. Here, the shape of the shell has to be designed according to the acting loads and the boundary conditions of the construction method. This paper describes the partly conflicting factors involved in the form-finding process for practical application and the semiautomated workflow for optimizing the geometry of shell bridges. In the first optimization step, the final bridge shape is determined using a particle-spring system or alternatively a thrust-network approach. In the second optimization step, the shell is completed to form a full dome—this is called the reference geometry and is required for the new construction method. Finally, the reference geometry is discretized into single-curved panels by using a mesh-based optimization framework. To frame the presented work, an overview of different experimental and computer-aided form-finding methods is given.

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42

Morikura and Miyata. "Effect of Mechanical Compression on Invasion Process of Malignant Melanoma Using In Vitro Three-Dimensional Cell Culture Device." Micromachines 10, no. 10 (September 30, 2019): 666. http://dx.doi.org/10.3390/mi10100666.

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Malignant melanoma in the plantar surface of the foot is subjected to various mechanical stimuli generated by daily human activity such as walking. Some studies have reported that mechanical compression affects the development and progression of melanoma. However, little is known about how mechanical compression affects the behavior of malignant melanoma cells in a physiological condition due to the complexity of the invasion mechanisms. In this study, we developed an in vitro three-dimensional cell culture device using microporous membrane in order to evaluate the effects of mechanical compression on the invasion process of malignant melanoma. Our results suggest that the invasion of melanoma cells under the compressive stress for 8 h of culture was promoted with the elongation of F-actin filaments compared to control groups, whereas there was no significant difference between both groups at 32 h of culture, with increasing cell death associated with promoting melanin synthesis. The results of this study contribute to the elucidation of the invasion mechanisms of malignant melanoma caused by mechanical stimulation.

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43

Kusters, Remy, Camille Simon, Rogério Lopes Dos Santos, Valentina Caorsi, Sangsong Wu, Jean-Francois Joanny, Pierre Sens, and Cecile Sykes. "Actin shells control buckling and wrinkling of biomembranes." Soft Matter 15, no. 47 (2019): 9647–53. http://dx.doi.org/10.1039/c9sm01902b.

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44

Yeremeyv, P. G., and D. B. Kiselev. "Thin Sheet Metal (Membrane) Suspended Roof Structures." International Journal of Space Structures 10, no. 4 (December 1995): 237–41. http://dx.doi.org/10.1177/026635119501000406.

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A membrane roof is a three-dimensional system of thin metal sagging sheets fastened along the perimeter to the supporting contour. The membrane can form the roof of buildings and structures of various shapes of the surface and in-plan outlines with spans of 18 to 300 m. The longer the span the higher the economic efficiency of the membranes, the thickness of which is as low as 1 to 5 mm. The distinctive features of the structure are the most complete use of strength properties of a thin sheet in compression and the continuation in one material of load bearing and enclosure functions. Such a structure is able to resist all types of force actions, wind and seismic ones being among them. The thin-sheet roof are easy to manufacture and erect. The membrane structures are intended for civil and industrial buildings. At present a wide complex of theoretical and experimental studies of the membrane structures is being carried out.

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45

Nagayama, Kazuaki, Yuki Kimura, Narutaka Makino, and Takeo Matsumoto. "Strain waveform dependence of stress fiber reorientation in cyclically stretched osteoblastic cells: effects of viscoelastic compression of stress fibers." American Journal of Physiology-Cell Physiology 302, no. 10 (May 15, 2012): C1469—C1478. http://dx.doi.org/10.1152/ajpcell.00155.2011.

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Actin stress fibers (SFs) of cells cultured on cyclically stretched substrate tend to reorient in the direction in which a normal strain of substrate becomes zero. However, little is known about the mechanism of this reorientation. Here we investigated the effects of cyclic stretch waveform on SF reorientation in osteoblastic cells. Cells adhering to silicone membranes were subjected to cyclic uniaxial stretch, having one of the following waveforms with an amplitude of 8% for 24 h: triangular, trapezoid, bottom hold, or peak hold. SF reorientation of these cells was then analyzed. No preferential orientation was observed for the triangular and the peak-hold waveforms, whereas SFs aligned mostly in the direction with zero normal strain (∼55°) with other waveforms, especially the trapezoid waveform, which had a hold time both at loaded and unloaded states. Viscoelastic properties of SFs were estimated in a quasi-in situ stress relaxation test using intact and SF-disrupted cells that maintained their shape on the substrate. The dynamics of tension FSFsacting on SFs during cyclic stretching were simulated using these properties. The simulation demonstrated that FSFsdecreased gradually during cyclic stretching and exhibited a compressive value (FSFs< 0). The magnitude and duration time of the compressive forces were relatively larger in the group with a trapezoid waveform. The frequency of SF orientation had a significant negative correlation with the applied compressive forces integrated with time in a strain cycle, and the integrated value was largest with the trapezoid waveform. These results may indicate that the applied compressive forces on SFs have a significant effect on the stretch-induced reorientation of SFs, and that SFs realigned to avoid their compression. Stress relaxation of SFs might be facilitated during the holding period in the trapezoid waveform, and depolymerization and reorientation of SFs were significantly accelerated by their viscoelastic compression.

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46

Kapustina, Maryna, Timothy C. Elston, and Ken Jacobson. "Compression and dilation of the membrane-cortex layer generates rapid changes in cell shape." Journal of Cell Biology 200, no. 1 (January 7, 2013): 95–108. http://dx.doi.org/10.1083/jcb.201204157.

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Rapid changes in cellular morphology require a cell body that is highly flexible yet retains sufficient strength to maintain structural integrity. We present a mechanism that meets both of these requirements. We demonstrate that compression (folding) and subsequent dilation (unfolding) of the coupled plasma membrane–cortex layer generates rapid shape transformations in rounded cells. Two- and three-dimensional live-cell images showed that the cyclic process of membrane-cortex compression and dilation resulted in a traveling wave of cortical actin density. We also demonstrate that the membrane-cortex traveling wave led to amoeboid-like cell migration. The compression–dilation hypothesis offers a mechanism for large-scale cell shape transformations that is complementary to blebbing, where the plasma membrane detaches from the actin cortex and is initially unsupported when the bleb extends as a result of cytosolic pressure. Our findings provide insight into the mechanisms that drive the rapid morphological changes that occur in many physiological contexts, such as amoeboid migration and cytokinesis.

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47

Cui, Liuliang, Xihong Zhang, Hong Hao, and Qingzhao Kong. "Improved resistance functions for RC elements accounting for compressive and tensile membrane actions." Engineering Structures 251 (January 2022): 113549. http://dx.doi.org/10.1016/j.engstruct.2021.113549.

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48

Yu, Hoi-Ying E., and William M. Bement. "Multiple Myosins Are Required to Coordinate Actin Assembly with Coat Compression during Compensatory Endocytosis." Molecular Biology of the Cell 18, no. 10 (October 2007): 4096–105. http://dx.doi.org/10.1091/mbc.e06-11-0993.

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Actin is involved in endocytosis in organisms ranging from yeast to mammals. In activated Xenopus eggs, exocytosing cortical granules (CGs) are surrounded by actin “coats,” which compress the exocytosing compartments, resulting in compensatory endocytosis. Here, we examined the roles of two myosins in actin coat compression. Myosin-2 is recruited to exocytosing CGs late in coat compression. Inhibition of myosin-2 slows coat compression without affecting actin assembly. This differs from phenotype induced by inhibition of actin assembly, where exocytosing CGs are trapped at the plasma membrane (PM) completely. Thus, coat compression is likely driven in part by actin assembly itself, but it requires myosin-2 for efficient completion. In contrast to myosin-2, the long-tailed myosin-1e is recruited to exocytosing CGs immediately after egg activation. Perturbation of myosin-1e results in partial actin coat assembly and induces CG collapse into the PM. Intriguingly, simultaneous inhibition of actin assembly and myosin-1e prevents CG collapse. Together, the results show that myosin-1e and myosin-2 are part of an intricate machinery that coordinates coat compression at exocytosing CGs.

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Maddala, Rupalatha, Mark Walters, Peter J. Brophy, Vann Bennett, and Ponugoti V. Rao. "Ankyrin-B directs membrane tethering of periaxin and is required for maintenance of lens fiber cell hexagonal shape and mechanics." American Journal of Physiology-Cell Physiology 310, no. 2 (January 15, 2016): C115—C126. http://dx.doi.org/10.1152/ajpcell.00111.2015.

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Periaxin (Prx), a PDZ domain protein expressed preferentially in myelinating Schwann cells and lens fibers, plays a key role in membrane scaffolding and cytoarchitecture. Little is known, however, about how Prx is anchored to the plasma membrane. Here we report that ankyrin-B (AnkB), a well-characterized adaptor protein involved in linking the spectrin-actin cytoskeleton to integral membrane proteins, is required for membrane association of Prx in lens fibers and colocalizes with Prx in hexagonal fiber cells. Under AnkB haploinsufficiency, Prx accumulates in the soluble fraction with a concomitant loss from the membrane-enriched fraction of mouse lenses. Moreover, AnkB haploinsufficiency induced age-dependent disruptions in fiber cell hexagonal geometry and radial alignment and decreased compressive stiffness in mouse lenses parallel to the changes observed in Prx null mouse lens. Both AnkB- and Prx-deficient mice exhibit disruptions in membrane organization of the spectrin-actin network and the dystrophin-glycoprotein complex in lens fiber cells. Taken together, these observations reveal that AnkB is required for Prx membrane anchoring and for maintenance of lens fiber cell hexagonal geometry, membrane skeleton organization, and biomechanics.

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50

Cámara, Candelaria Ines, Matías Ariel Crosio, Ana Valeria Juarez, and Natalia Wilke. "Dexamethasone and Dexamethasone Phosphate: Effect on DMPC Membrane Models." Pharmaceutics 15, no. 3 (March 4, 2023): 844. http://dx.doi.org/10.3390/pharmaceutics15030844.

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Dexamethasone (Dex) and Dexamethasone phosphate (Dex-P) are synthetic glucocorticoids with high anti-inflammatory and immunosuppressive actions that gained visibility because they reduce the mortality in critical patients with COVID-19 connected to assisted breathing. They have been widely used for the treatment of several diseases and in patients under chronic treatments, thus, it is important to understand their interaction with membranes, the first barrier when these drugs get into the body. Here, the effect of Dex and Dex-P on dimyiristoylphophatidylcholine (DMPC) membranes were studied using Langmuir films and vesicles. Our results indicate that the presence of Dex in DMPC monolayers makes them more compressible and less reflective, induces the appearance of aggregates, and suppresses the Liquid Expanded/Liquid Condensed (LE/LC) phase transition. The phosphorylated drug, Dex-P, also induces the formation of aggregates in DMPC/Dex-P films, but without disturbing the LE/LC phase transition and reflectivity. Insertion experiments demonstrate that Dex induces larger changes in surface pressure than Dex-P, due to its higher hydrophobic character. Both drugs can penetrate membranes at high lipid packings. Vesicle shape fluctuation analysis shows that Dex-P adsorption on GUVs of DMPC decreases membrane deformability. In conclusion, both drugs can penetrate and alter the mechanical properties of DMPC membranes.

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