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考虑高温损伤影响玻化微珠混凝土氯离子传输模拟分析

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太原理工大学学报 2023年

作者：晋卓阳李明厚 SELYUTINA Nina smirnov ivan 刘元珍张玉太原理工大学土木工程学院 Saint Petersburg State University

火灾高温引起的隧道衬砌结构开裂损伤往往会对结构耐久性维持埋下巨大隐患。基于此，通过MATLAB和COMSOL软件交互使用，建立了包含粗骨料、玻化微珠、砂浆和界面过渡区的玻化微珠混凝土（GIC）凸多边形骨料数值模型，开展了考虑高温影... 详细信息

火灾高温引起的隧道衬砌结构开裂损伤往往会对结构耐久性维持埋下巨大隐患。基于此，通过MATLAB和COMSOL软件交互使用，建立了包含粗骨料、玻化微珠、砂浆和界面过渡区的玻化微珠混凝土（GIC）凸多边形骨料数值模型，开展了考虑高温影响的氯离子传输模拟并进行了有效性验证。依据钢筋脱钝寿命理论，建立了灾后服役寿命参数影响评价机制。结果表明：随着玻化微珠体积分数的增加、界面过渡区厚度的减小及最大骨料直径的增大，混凝土灾后服役寿命得到一定改善，其中，玻化微珠体积分数影响尤为显著。基于参数分析，通过单因素相关性分析及多元非线性分析方法，最终建立了考虑高温影响的耐久性极限状态函数，可为实际工程中建筑结构设计及灾后寿命评估提供参考。

关键词：玻化微珠混凝土高温氯离子传输数值模拟服役寿命

Self-healable and Robust Film Based on Electroactive Polymer Brush as Electrode for Flexible Supercapacitor

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Chinese Journal of Polymer Science 2024年第8期42卷 1049-1059页

作者： Maria P.Sokolova Vitaly K.Vorobiov Nikolay N.smirnov ivan S.Kuryndin Natalya V.Bobrova Michael A.smirnov Institute of Macromolecular Compounds Russian Academy of SciencesBolshoy pr.31Saint Petersburg 199004Russia

The aim of this study was to develop self-healable and robust elect roconductive film based on polyaniline copolymer for application as electrode in flexible *** this purpose,the electroconductive polymer brushes(EPB)was *** synthesis of EPB is based on graft polymerizations of acrylamide(AAm)on poly(vinyl alcohol)(PVA)with formation of PVA-PAAm polymer brush and subsequent graft copolymerization of aniline and p-phenylenediamine on PVA-PAAm resulting in formation of EPB with electroconducting copoly(aniline-co-pphenylenediamine)(PAPh DA).It was found that the ratio between PVA and PAAm at the first stage greatly influence the electrochemical performance of the *** films were prepared by casting of EPB solution with subsequent *** of electrical current distribution through the film with AFM reveal more uniform distribution of PAPhDA in EPB in comparison with reference PVA-PAPhDA and PAAm-PAPhDA *** was demonstrated that mechanical cha racteristics and electrical conductivity values of films restore at large extent after curring and self-healing under optimal relative humidity level(58%).The flexile supercapacitor cell with EPB film electrodes demon strate specific capacitance 602 mF·cm^(-2)at the current density of 1 mA·cm^(-2)and retention 94%of initial capacitance after 5000 charge/discharge cycles.

关键词： Polymer brush Polyaniline Flexible supercapacitor Self-healing Electroconducting film

基于热裂纹演化的玻化微珠保温混凝土渗透性能分析

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浙江大学学报（工学版） 2023年第2期57卷 367-379页

作者：李明厚 SELYUTINA Nina smirnov ivan 张祥李贝贝刘元珍张玉太原理工大学土木工程学院山西太原030024 Saint Petersburg State University St.Petersburg 199034Russia

为了改善火灾后混凝土结构耐久性退化问题,利用玻化微珠(GHB)的高热稳定性对混凝土耐高温性能进行提升,通过电通量法对高温后玻化微珠保温混凝土(GIC)的抗氯离子侵蚀性能进行测试,并结合混凝土试件热裂纹演化特征对其抗氯离子侵蚀性能... 详细信息

为了改善火灾后混凝土结构耐久性退化问题,利用玻化微珠(GHB)的高热稳定性对混凝土耐高温性能进行提升,通过电通量法对高温后玻化微珠保温混凝土(GIC)的抗氯离子侵蚀性能进行测试,并结合混凝土试件热裂纹演化特征对其抗氯离子侵蚀性能劣化规律进行分析.结果表明:GHB的掺加显著改善了高温后混凝土抗氯离子渗透能力退化问题,与同强度等级的普通混凝土(NC)和硅灰混凝土(SFC)相比,掺加GHB后混凝土的电通量分别降低了约54.15%、32.69%.结合各试件热裂纹演化规律,认为这归因于GHB和硅灰对混凝土密实性的提高,以及GHB对混凝土抗高温损伤造成的积极影响.在此基础上,通过考虑热裂纹演化特征、GHB和硅灰的影响,建立了高温环境氯离子渗透性预测模型.

关键词：玻化微珠混凝土氯离子侵蚀热裂纹预测模型

基于X-CT的高温后再生保温混凝土损伤分析

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复合材料学报 2022年第6期39卷 2829-2843页

作者：苗艳春张玉 SELYUTINA Nina smirnov ivan 邓克招李贝贝都思哲刘元珍马钢太原理工大学土木工程学院太原030024 华南理工大学亚热带建筑科学国家重点实验室广州510640 圣彼得堡国立大学圣彼得堡199034

火灾的发生往往会导致混凝土材料微细观结构的损伤劣化,体现在水化物分解、孔隙结构粗化、热开裂和水汽压力升高诱致开裂等,继而导致材料宏观力学性能及耐久性的下降。轻质高强、内部多孔、高热稳定的玻化微珠(GHB)的细观调控功能可实... 详细信息

火灾的发生往往会导致混凝土材料微细观结构的损伤劣化,体现在水化物分解、孔隙结构粗化、热开裂和水汽压力升高诱致开裂等,继而导致材料宏观力学性能及耐久性的下降。轻质高强、内部多孔、高热稳定的玻化微珠(GHB)的细观调控功能可实现混凝土耐高温性能的提升。为了研究受高温作用的再生保温混凝土(RATIC)内部细观结构及裂纹变化特征,本研究首先对高温作用后的RATIC开展了立方体抗压强度试验和CT扫描试验,之后利用基于改进的自适应阈值法和区域生长法的图像分割算法,建立了基于真实结构的RATIC细观模型,分析了不同GHB及再生骨料(RCA)掺量的RATIC试件随温度变化时其内部微裂纹的孕育、萌生、发展及贯通过程。并对RATIC破坏形态与CT结果进行了对比分析。研究结果表明:GHB对裂缝的延伸有显著阻断作用,为蒸汽压提供了释放通道,缓解了砂浆区域、孔隙边界处的开裂,减缓了热量的传播,提升了混凝土抗热致损伤性能。

关键词：再生保温混凝土高温 CT 图像分割细观模型

Method for passivation of propellant residues in orbital stage tank of launch vehicle

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Chinese Journal of Aeronautics 2024年第1期37卷 64-76页

作者： Valeriy TRUSHLYAKOV ivan LESNYAK Alexey PANICHKIN Department of Aviation and Rocket Building Omsk State Technical UniversityOmsk 644050Russia Sobolev Institute of Mathematics of the Siberian Branch of Russian Academy of Sciences Novosibirsk 630090Russia

The problem of removing unused liquid propellant residues from the tanks of spent spacecraft and orbital stages of Launch Vehicles(LV)leads to their explosion and the formation of space debris in *** provide a solution to this problem,a method for removing liquid propellant residues from the LV tanks after the mission completion is *** method is based on the gasification of liquid propellant residues in the tanks under acoustic-vacuum exposure and the discharge of the gasification products into the surrounding outer *** investigations were carried out on a Ground-based Experimental Installation(GEI)to determine the coefficient of heat transfer from the surface of an acoustic radiator to a *** obtained coefficient was then used to calculate the energy costs for the gasification of *** estimates are given on the example of the tank with kerosene residues from a spent second stage of the LV“Soyuz-2.1 v”.The optimal discharge rate at which kerosene does not freeze is 0.14 m^(3)/***,the acoustic exposure leads to an increase in the mass of evaporated kerosene over a given time by96.1%,and the energy costs are 1756.7 kJ(approximately 50% of the remaining electrical energy).

关键词： Propellant Weightlessness Liquid evaporation Heat and mass transfer Acoustics Vacuum Vapor bubbles

Oscillatory Dynamics of a Spherical Solid in a Liquid in an Axisymmetric Variable Cross Section Channel

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1219-1232页

作者： ivan Karpunin Laboratory of Vibrational Hydromechanics Perm State Humanitarian Pedagogical UniversityPerm614990Russia

The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally *** is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel *** intensity and direction of these flows depend on the dimensionless oscillating *** the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each *** a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average *** is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the *** quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless *** behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in *** findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.

关键词： Phase inclusion axisymmetric channel variable cross section oscillations dimensionless frequency averaged force viscous boundary layer

Liquid superlubricity of lubricants containing hydroxyl groups and their aqueous solution under rolling/sliding conditions

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Friction 2024年第1期12卷 164-173页

作者： Tomáš POLÁČEK Petr ŠPERKA ivan KŘUPKA Faculty of Mechanical Engineering Brno University of TechnologyBrno 61669Czech Republic

Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous *** were carried out on an optical ball-on-disc tribometer under rolling/sliding *** film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body *** results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based *** studied liquids themselves are almost *** the addition of water,the signs of shear thinning behavior disappear even *** conditions for this type of lubricant can be predicted using the known Hamrock–Dowson *** anomaly in the thickness of the lubricants was observed as an abrupt change at certain *** more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.

关键词： macroscale superlubricity super low traction water-based lubricants elastohydrodynamic lubrication(EHL) film thickness

Applying the Shearlet-Based Complexity Measure for Analyzing Mass Transfer in Continuous-Flow Microchannels

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1743-1758页

作者： Elena Mosheva ivan Krasnyakov Institute of Continuous Media Mechanics UB RAS Perm614013Russia Department of Applied Physics Perm National Research Polytechnic UniversityPerm614990Russia

Continuous-flow microchannels are widely employed for synthesizing various materials,including nanoparticles,polymers,and metal-organic frameworks(MOFs),to name a *** technology allows precise control over reaction parameters,resulting in purer,more uniform,and structurally stable products due to more effective mass transfer ***,continuous-flow synthesis processes may be accompanied by the emergence of spatial convective structures initiating convective *** the one hand,convection can accelerate reactions by intensifying mass *** the other hand,it may lead to non-uniformity in the final product or defects,especially in MOF microcrystal *** ability to distinguish regions of convective and diffusive mass transfer may be the key to performing higher-quality reactions and obtaining purer *** this study,we investigate,for the first time,the possibility of using the information complexity measure as a criterion for assessing the intensity of mass transfer in microchannels,considering both spatial and temporal non-uniformities of liquid’s distributions resulting from convection *** calculate the complexity using shearlet transform based on a local *** contrast to existing methods for calculating complexity,the shearlet transform based approach provides a more detailed representation of local *** analysis involves experimental images illustrating the mixing process of two non-reactive liquids in a Y-type continuous-flow microchannel under conditions of double-diffusive convection *** obtained complexity fields characterize the mixing process and structure formation,revealing variations in mass transfer intensity along the *** compare the results with cases of liquid mixing via a pure diffusive *** analysis,it was revealed that the complexity measure exhibits sensitivity to variations in the type of mass transfer,establishing its feasibility as an ind

关键词： Shearlet analysis complexity measure entropy measure convection microchannels double-diffusive instability

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高温后再生保温混凝土损伤劣化数值分析

太原理工大学学报 2022年

作者：刘淑钰苗艳春李明厚李贝贝 SELYUTINA Nina smirnov ivan 刘元珍张玉太原理工大学土木工程学院 Saint Petersburg State University

近年来，随着建筑火灾的频繁发生，由于高温引起的混凝土内部微细观结构的损伤劣化，进而导致其宏观力学性能的退化问题引起了人们的广泛关注。而内部多孔且高温稳定的玻化微珠（glazed hollow beads，GHB）可在一定程度上缓减混凝土的...

近年来，随着建筑火灾的频繁发生，由于高温引起的混凝土内部微细观结构的损伤劣化，进而导致其宏观力学性能的退化问题引起了人们的广泛关注。而内部多孔且高温稳定的玻化微珠（glazed hollow beads，GHB）可在一定程度上缓减混凝土的高温损伤劣化，提升混凝土的抗火性能。为了进一步明确GHB改善混凝土抗火性能的机理，本研究从细观尺度出发，首先提出了一种可考虑初始缺陷和再生骨料（recycled coarse aggregate，RCA）取代率的再生保温混凝土（recycled aggregate concrete mixed with glazed hollow beads，RATIC）细观模型的建模方法，之后利用现阶段比较常用的塑性损伤模型，探究了RCA取代率（0，50%，100%）、GHB含量（0，70%，100%）和孔隙率（0，2%，4%）对于高温后RATIC力学性能的影响。结果表明：随着受火温度的提高，荷载作用下RATIC试件的损伤分布均呈现出逐渐加剧的趋势，且500℃后，试件的损伤分布较400℃之前严重。GHB的加入可在一定程度上缓减混凝土内部的损伤劣化，而RCA的加入会加剧此现象。此外，随着孔隙率增大，RATIC试件的强度逐渐变低。

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