An efficient homogenization scheme for analyzing the elastic properties of hybrid nanocomposites filled with multiscale particles

This paper deals with numerical modelling of the elastic properties of the rice straw-clay composite. This composite material is currently attracting interest because of its low impact on the environment but also for economic reasons. Benefiting from the advantages of a promising building material, straw reinforced composites attract more attention. This work allowed to model the effect of the straw inclusions on the elastic properties of the composite by a numerical approach considering the aspect ratio, the volume fraction, the orientation and the distribution of the straw inclusions. The Mori-Tanaka homogenization scheme for the RVEs is done using Digimat-MF software and the 3D composite microstructure models are generated by the Digimat-FE software. This made it possible to calculate the effective elastic properties of the clay-rice straw composites by numerical simulation. An empirical linear correlation between the volume fraction of the inclusions and the Young's modulus has been proposed. The results obtained can help to better control the formulation of the composite in developing countries.

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On the effective anisotropic elastic properties of porous hydroxyapatite, porous collagen, and cortical bone: A homogenization scheme with percolation threshold concept

Mathematics and Mechanics of Solids ◽

10.1177/1081286518769961 ◽

2018 ◽

Vol 24 (4) ◽

pp. 1091-1102 ◽

Cited By ~ 1

Author(s):

Mai-Ba Vu ◽

Tuan Nguyen-Sy

Keyword(s):

Percolation Threshold ◽

Cortical Bone ◽

Elastic Properties ◽

Organic Content ◽

Homogenization Theory ◽

High Porosity ◽

Porous Hydroxyapatite ◽

Threshold Concept ◽

Homogenization Scheme ◽

Anisotropic Elastic

The objective of this study is to model the effective anisotropic elastic properties of porous hydroxyapatite, wet collagen, and cortical bone by an advanced homogenization scheme with a percolation threshold concept. The theoretical basis of the anisotropic homogenization theory is first presented. A homogenization scheme with a percolation threshold concept is then introduced and validated against experimental data for porous hydroxyapatite as well as bone after decollagenization. It is also validated on a porous collagen that is a result of the demineralization of bone. Even though aligned collagen fibers are considered, similar values of the elastic stiffnesses [Formula: see text] and [Formula: see text] were found for demineralized bone due to its very high porosity. Finally the proposed method is used to model cortical bone as a mixture of hydroxyapatite mineral and soft organic content that is in turn a mixture of collagen fiber and pores filled by water. Good agreement between modeled and measured data is observed. The model presented herein is simpler than existing multi-scale homogenization schemes in the literature, but its results fit very well with the experimented trends.

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Nanotechnology and construction: use of nanoindentation measurements to predict macroscale elastic properties of high strength cementitious composites

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952012000300002 ◽

2012 ◽

Vol 5 (3) ◽

pp. 284-295 ◽

Cited By ~ 1

Author(s):

W. R. L. da Silva ◽

J. Němeček ◽

P. Štemberk

Keyword(s):

Compressive Strength ◽

Elastic Properties ◽

High Performance ◽

Elastic Moduli ◽

High Strength ◽

Cementitious Composites ◽

Strength Tests ◽

Subsequent Phase ◽

Homogenization Scheme ◽

Analytical Homogenization

This paper aims to present the experimental results involving the use of nanoindentation measurements and prediction of macroscale elastic properties of high performance cementitious composites (HPCC). The elastic properties of HPCC mixture were evaluated at different length scales by nanoindentation (microscale), and elastic moduli and compressive strength tests (macroscale). The nanoindentation results, obtained by grid indentation with subsequent phase deconvolution, were complemented by an independent porosimetry test and inserted into a two-step analytical homogenization scheme to predict the overall macroscale properties. The final results show that the presented method allows a reliable advanced prediction of HPCC elastic properties indicating, thus, that inserting nanotechnology in the concrete industry can be promising, since it would allow the production of a more predictable composite in an easier and less expensive way.

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Effect of graphene nanoplatelets addition on the elastic properties of short ceramic fiber-reinforced aluminum-based hybrid nanocomposites

Mechanics Based Design of Structures and Machines ◽

10.1080/15397734.2020.1753535 ◽

2020 ◽

pp. 1-17 ◽

Cited By ~ 2

Author(s):

Dangquan Zhang ◽

Muhammad Aqeel Ashraf ◽

Zhenling Liu ◽

Cheng Li ◽

Wanxi Peng

Keyword(s):

Elastic Properties ◽

Graphene Nanoplatelets ◽

Hybrid Nanocomposites ◽

Ceramic Fiber ◽

Fiber Reinforced

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Electron Microscopy and image reconstruction reveal the structural basis for spectrin's elastic properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122952 ◽

1992 ◽

Vol 50 (1) ◽

pp. 510-511

Author(s):

Amy M. McGough ◽

Robert Josephs

Keyword(s):

Electron Microscopy ◽

Elastic Properties ◽

Conformational Changes ◽

Quaternary Structure ◽

Three Dimensional ◽

Membrane Skeleton ◽

Projection Algorithm ◽

Structural Basis ◽

Iterative Approximation ◽

Membrane Skeletons

The remarkable deformability of the erythrocyte derives in large part from the elastic properties of spectrin, the major component of the membrane skeleton. It is generally accepted that spectrin's elasticity arises from marked conformational changes which include variations in its overall length (1). In this work the structure of spectrin in partially expanded membrane skeletons was studied by electron microscopy to determine the molecular basis for spectrin's elastic properties. Spectrin molecules were analysed with respect to three features: length, conformation, and quaternary structure. The results of these studies lead to a model of how spectrin mediates the elastic deformation of the erythrocyte.Membrane skeletons were isolated from erythrocyte membrane ghosts, negatively stained, and examined by transmission electron microscopy (2). Particle lengths and end-to-end distances were measured from enlarged prints using the computer program MACMEASURE. Spectrin conformation (straightness) was assessed by calculating the particles’ correlation length by iterative approximation (3). Digitised spectrin images were correlation averaged or Fourier filtered to improve their signal-to-noise ratios. Three-dimensional reconstructions were performed using a suite of programs which were based on the filtered back-projection algorithm and executed on a cluster of Microvax 3200 workstations (4).

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The buckling of thin EM specimens

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177386 ◽

1990 ◽

Vol 48 (4) ◽

pp. 850-851

Author(s):

A.R. Thölén

Keyword(s):

Electron Microscope ◽

Elastic Properties ◽

Crystal Surface ◽

Specimen Surface ◽

Radius Of Curvature ◽

Thin Foils ◽

Thin Electron ◽

Regular Patterns

Thin electron microscope specimens often contain irregular bend contours (Figs. 1-3). Very regular bend patterns have, however, been observed around holes in some ion-milled specimens. The purpose of this investigation is twofold. Firstly, to find the geometry of bent specimens and the elastic properties of extremely thin foils and secondly, to obtain more information about the background to the observed regular patterns.The specimen surface is described by z = f(x,y,p), where p is a parameter, eg. the radius of curvature of a sphere. The beam is entering along the z—direction, which coincides with the foil normal, FN, of the undisturbed crystal surface (z = 0). We have here used FN = [001]. Furthermore some low indexed reflections are chosen around the pole FN and in our fcc crystal the following g-vectors are selected:

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