Microstructural Analysis of Three-dimensional Permeabilities of Textile Composites by the Homogenization Theory

A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO) phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld?s structure refinement method. The resulting lattice parameters, relative phase abundances, crystallite sizes and crystal lattice microstrains were determined as a function of milling time. Microstructural analysis showed a little difference in morphology of obtained powders. The primary particles, irregular in shape and smaller than 400 nm are observed clearly, although they have assembled together to form agglomerates with varying size and morphology. Dense BFO ceramics were prepared by conventional solid-state reaction at the temperature of 810?C for 1h followed immediately by quenching process. [Projekat Ministarstva nauke Republike Srbije, br. III45007: Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processing

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Mechanical Characterization of Fiber Fabrics

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 1 ◽

10.1115/esda2010-25300 ◽

2010 ◽

Author(s):

Iulian-Gabriel Birsan ◽

Adrian Circiumaru ◽

Vasile Bria ◽

Igor Roman ◽

Victor Ungureanu

Keyword(s):

Carbon Fiber ◽

Polymer Matrix ◽

Complex Structure ◽

Three Dimensional ◽

Textile Composites ◽

Simple Type ◽

Carbon Filaments ◽

Elastic Interface ◽

Fiber Fabric

Fabric reinforced or textile composites are increasingly used in aerospace, automotive, naval and other applications. They are convenient material forms providing adequate stiffness and strength in many structures. In such applications they are subjected to three-dimensional states of stress coupled with hydro-thermal effects. Assuming that a composite material is a complex structure it is obvious that is hard to describe all its properties in terms of its parts properties. The properties of the composite depend not only on the properties of the components but on quality and nature of the interface between the components and its properties. As reinforcement two types of fiber fabric were used; first one is a simple type fabric of untwisted tows of carbon filaments while the second one is also simple type but as yarn and fill are used alternately untwisted tows of carbon and aramide filaments. There were some problems to be solved before molding: fabric stability during handling, cutting, imbuing the carbon and aramide tows are slipping one on each other leading to fabric defects; generally the epoxy systems do not adhere to the carbon fiber; in order to obtain a valuable material the nature of interface must be the same for polymer-carbon fiber and polymer aramide fiber. In order to solve these problems the two fabrics were covered (by spraying) with a thin film of PNB rubber. Into the rubber solution were also dispersed small amounts of clay (to create a better interface) and carbon black (to improve the electrical conductivity). The rubber presence solves the fabric stability problem; ensures the same type of interface between fibers and polymer matrix; ensures a more elastic interface between fibers and polymer matrix. This treatment induces modification on tensile behavior of fabrics. This study is about mechanical evaluation of such fabrics.

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Electrostatic-Interaction-Driven Assembly of Binary Hybrids towards Fire-Safe Epoxy Resin Nanocomposites

Polymers ◽

10.3390/polym11020229 ◽

2019 ◽

Vol 11 (2) ◽

pp. 229 ◽

Cited By ~ 3

Author(s):

Lu Liu ◽

Wei Wang ◽

Yongqian Shi ◽

Libi Fu ◽

Lulu Xu ◽

...

Keyword(s):

Heat Release ◽

High Performance ◽

Flame Retardants ◽

Microstructural Analysis ◽

Three Dimensional ◽

Morphological Characterization ◽

Interfacial Interaction ◽

Graphitization Degree ◽

Cone Calorimeter Test ◽

Ep Matrix

Manganese dioxide (MnO2), as a promising green material, has recently attracted considerable attention of researchers from various fields. In this work, a facile method was introduced to prepare binary hybrids by fabricating three-dimensional (3D) zinc hydroxystannate (ZHS) cubes on two-dimensional (2D) MnO2 nanosheets towards excellent flame retardancy and toxic effluent elimination of epoxy (EP) resin. Microstructural analysis confirmed that the morphologies and structures of MnO2@ZHS binary hybrids were well characterized, implying the successful synthesis. Additionally, the morphological characterization indicated that MnO2@ZHS binary hybrids could achieve satisfactory interfacial interaction with the EP matrix and be well dispersed in nanocomposites. Cone calorimeter test suggested that MnO2@ZHS binary hybrids effectively suppressed the peak of heat release rate and total heat release of EP nanocomposites, performing better than MnO2 or ZHS alone. Condensed-phase analysis revealed that MnO2@ZHS binary hybrids could promote the char density and graphitization degree of char residues and thereby successfully retard the permeation of oxygen and flammable gases. Moreover, through the analysis of gas phase, it can be concluded that MnO2@ZHS binary hybrids could efficiently suppress the production of toxic gases during the degradation of EP nanocomposites. This work implies that the construction of 2D/3D binary hybrids with an interfacial interaction is an effective way to fabricate high-performance flame retardants for EP.

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Investigation of the classification and properties of three-dimensional textile fabrics

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925019889960 ◽

2019 ◽

Vol 14 ◽

pp. 155892501988996

Author(s):

Zhenyu Ma ◽

Pingze Zhang ◽

Jianxun Zhu

Keyword(s):

Three Dimensional ◽

Physical And Mechanical Properties ◽

Structural Features ◽

Textile Composites ◽

Uniform Structure ◽

Fiber Volume ◽

Textile Fabrics ◽

And Performance ◽

Relationship Of ◽

The Relationship

Three-dimensional textile fabrics are used as the reinforcing phase of the textile structural composites, and their geometry affect the physical and mechanical properties of composites. Based on the curvature and directions of the fiber tows in three-dimensional textile fabrics, four representative geometric units are proposed, namely, the orthogonal geometric unit, the curved geometric unit, the skew geometric unit, and the uniform distribution unit, respectively. Other units are the combinations or derivations of these representative geometric units. The relationship and performance characteristics of these representative geometric units are discussed in section “The relationship of RGUs.” The structural features of three-dimensional textile fabrics are illustrated on the mesoscopic scale, and the models are established to predict the geometric properties. The concepts of fabrics with stable structure, flexible structure, elastoplastic structure, and uniform structure are proposed. The fiber volume fractions and elastic characteristics of different structural fabrics are discussed. The classification of three-dimensional textile fabrics is conducive to investigate the relationship between geometry and property, forming a technical system and providing a theoretical basis for the selection of three-dimensional structural textile composites with different performance.

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The Asymptotic Homogenization Method of the Settlement Calculation of the Cement-Soil Pile Composite Foundation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.390 ◽

2011 ◽

Vol 217-218 ◽

pp. 390-395

Author(s):

Ming Qin Guo ◽

Jie Li ◽

Shi Cheng Ma ◽

Zhi Lin Liu

Keyword(s):

Elastic Foundation ◽

Three Dimensional ◽

Elastic Parameter ◽

Homogenization Method ◽

Calculation Model ◽

Composite Foundation ◽

Homogenization Theory ◽

Asymptotic Homogenization ◽

Asymptotic Homogenization Method ◽

Cement Soil

The finite element calculation model of the cement-soil pile composite foundation based on asymptotic homogenization theory has been built, under the state of three-dimensional stress, the equivalent elastic parameter of the composite elastic foundation model has been calculated, and depending on which, the settlement quantity has been calculated. Analysis through comparison with the testing result shows that it is feasible to use the homogenization method for calculating the settlement quantity of the composite elastic foundation, which sets up a theoretical basis for further analysis of homogenization method about composite foundation.

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