Influence of the number of layers on the equilibrium of a granular packing

2000 ◽  
Vol 62 (1) ◽  
pp. 738-743 ◽  
Author(s):  
M. A. Aguirre ◽  
N. Nerone ◽  
A. Calvo ◽  
I. Ippolito ◽  
D. Bideau
Keyword(s):  
Granular Packing ◽  
Number Of Layers

Diffusion

2018 ◽  
Author(s):  
Ginestra Bianconi
Keyword(s):  
Random Walks ◽  
Spectral Properties ◽  
Diffusion Constant ◽  
Network Structures ◽  
Multilayer Networks ◽  
Multilayer Network ◽  
Lévy Walk ◽  
Number Of Layers ◽  
Levy Walk ◽  
Speed Up

This chapter addresses diffusion, random walks and congestion in multilayer networks. Here it is revealed that diffusion on a multilayer network can be significantly speed up with respect to diffusion taking place on its single layers taken in isolation, and that sometimes it is possible also to observe super-diffusion. Diffusion is here characterized on multilayer network structures by studying the spectral properties of the supra-Laplacian and the dependence on the diffusion constant among different layers. Random walks and its variations including the Lévy Walk are shown to reflect the improved navigability of multilayer networks with more layers. These results are here compared with the results of traffic on multilayer networks that, on the contrary, point out that increasing the number of layers could be detrimental and could lead to congestion.

scholarly journals Stochastic Thermal Properties of Laminates Filled with Long Fibers

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2511
Author(s):  
Jan Turant
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Cross Section ◽  
Circular Cross Section ◽  
Saturation Density ◽  
Composite Matrix ◽  
Number Of Layers ◽  
Stochastic Parameters ◽  
Multilayer Composites ◽  
Long Fibers

In this paper, the stochastic parameters of the effective thermal conductivity of multilayer composites are considered. The examined specimens of composites were built with a different number of layers and each had a different saturation density of a composite matrix with fibers. For each case of laminate built with a prescribed number of layers and assumed saturation density, 10,000 tests of its effective thermal conductivity were carried out using numerical experiments. It was assumed that the fibers located in each layer were rectilinear, had a circular cross-section and that they could take random positions in their repeatable volume elements (RVEs). In view of the mentioned assumptions, the heat flux passing throughout a cross-section of a composite sample, perpendicular to the fibers’ direction, was considered. The probability density functions were fitted to the obtained data and then the chosen stochastic parameters of the effective thermal conductivity coefficients were determined.

scholarly journals Experimental and Numerical Analyses on the Buckling Characteristics of Woven Flax/Epoxy Laminated Composite Plate under Axial Compression

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 995
Author(s):  
Venkatachalam Gopalan ◽  
Vimalanand Suthenthiraveerappa ◽  
Jefferson Stanley David ◽  
Jeyanthi Subramanian ◽  
A. Raja Annamalai ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Composite Plate ◽  
Compressive Load ◽  
Laminated Composite ◽  
Green Composite ◽  
Laminated Composite Plate ◽  
Axial Compressive Load ◽  
Number Of Layers ◽  
Structural Applications ◽  
Ply Orientation

The evolution of a sustainable green composite in various loadbearing structural applications tends to reduce pollution, which in turn enhances environmental sustainability. This work is an attempt to promote a sustainable green composite in buckling loadbearing structural applications. In order to use the green composite in various structural applications, the knowledge on its structural stability is a must. As the structural instability leads to the buckling of the composite structure when it is under an axial compressive load, the work on its buckling characteristics is important. In this work, the buckling characteristics of a woven flax/bio epoxy (WFBE) laminated composite plate are investigated experimentally and numerically when subjected to an axial compressive load. In order to accomplish the optimization study on the buckling characteristics of the composite plate among various structural criterions such as number of layers, the width of the plate and the ply orientation, the optimization tool “response surface methodology” (RSM) is used in this work. The validation of the developed finite element model in Analysis System (ANSYS) version 16 is carried out by comparing the critical buckling loads obtained from the experimental test and numerical simulation for three out of twenty samples. A comparison is then made between the numerical results obtained through ANSYS16 and the results generated using the regression equation. It is concluded that the buckling strength of the composite escalates with the number of layers, the change in width and the ply orientation. It is also noted that the weaving model of the fabric powers the buckling behavior of the composite. This work explores the feasibility of the use of the developed green composite in various buckling loadbearing structural applications. Due to the compromised buckling characteristics of the green composite with the synthetic composite, it has the capability of replacing many synthetic composites, which in turn enhances the sustainability of the environment.

Effect of the number of layers on determination of spin asymmetries in current-perpendicular-to-plane giant magnetoresistance

2011 ◽  
Vol 98 (4) ◽  
pp. 042503 ◽  
Author(s):  
Tomohiro Taniguchi ◽  
Hiroshi Imamura ◽  
Tomoya M. Nakatani ◽  
Kazuhiro Hono
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Asymmetries ◽  
Number Of Layers ◽  
Current Perpendicular To Plane

Acoustic characterization of silica nanoparticle-impregnated Kevlar fabric

2021 ◽  
pp. 004051752110238
Author(s):  
Oluwafemi P Akinmolayan ◽  
James M Manimala
Keyword(s):  
Transmission Loss ◽  
Silica Nanoparticle ◽  
Air Gap ◽  
Thin Plates ◽  
Residual Porosity ◽  
Ballistic Performance ◽  
Number Of Layers ◽  
Structural Applications ◽  
Acoustic Characterization

Silica nanoparticle-impregnated Kevlar (SNK) fabric has better specific ballistic performance in comparison to its neat counterparts. For multifunctional structural applications using lightweight composites, combining this improved ballistic functionality with an acoustic functionality is desirable. In this study, acoustic characterization of neat and SNK samples is conducted using the normal-incidence impedance tube method. Both the absorption coefficient and transmission loss (TL) are measured in the 60–6000 Hz frequency range. The influence of parameters such as number of layers of neat or treated fabric, percentage by weight of nanoparticle addition, spacing between fabric layers, and residual porosity is examined. It is found that while absorption decreases with an increase in nanoparticle addition for frequencies above about 2500 Hz, increasing the number of layers shifts peak absorption to lower frequencies. By introducing an air-gap behind the fabric layer, dominant low-frequency (1000–3000 Hz) absorption peaks are obtained that correlate well with natural modes of mass-equivalent thin plates. Examining the influence of residual porosity by laminating the SNK samples reveals that it contributes to about 30–50% of the total absorption. Above about 1500 Hz, 3–5 dB of TL increase is obtained for SNK samples vis-à-vis the neat samples. TL is found to increase beyond that of the neat sample above a threshold frequency when an air-gap is introduced between two SNK layers. With an increase in the weight of nanoparticle addition, measured TL tends to be closer to mass law predictions. This study demonstrates that SNK fabric could provide improved acoustic performance in addition to its ballistic capabilities, making it suitable for multifunctional applications and could form the basis for the development of simplified models to predict the structural acoustic response of such nanoparticle–fabric composites.

Investigations on Dynamic Puncture Behaviors of Integrated Composite Reinforced with Varying Fabrics

2013 ◽  
Vol 365-366 ◽  
pp. 1070-1073 ◽  
Author(s):  
Chia Chang Lin ◽  
Ting Ting Li ◽  
Ching Wen Lou ◽  
Jan Yi Lin ◽  
Jia Horng Lin
Keyword(s):  
Performance Improvement ◽  
Cost Reduction ◽  
Body Armor ◽  
Packaging Materials ◽  
Puncture Resistance ◽  
Fabric Reinforcement ◽  
Number Of Layers ◽  
Layer Composite ◽  
Puncture Force ◽  
And Performance

The dynamic puncture resistance of multi-layer integrated composite which was comprised of glass fabric reinforcement or Kevlar fabric reinforcement and nonwovens were discussed as related to recycled Kevlar fibers amount, number of layer and K-ply position for purpose of cost reduction and performance improvement. The result shows that, 20 wt% Kevlar fibers contained in nonwovens have the optimum puncture resistance. And the dynamic puncture force increases linearly with number of layers, and also improves proportionally as increasing number of K-ply. The resultant multi-layer composite is expected to be used as body armor interlayer and packaging materials.

scholarly journals Intruder mobility in a vibrated granular packing

2011 ◽  
Vol 96 (5) ◽  
pp. 54003 ◽  
Author(s):  
R. Harich ◽  
T. Darnige ◽  
E. Kolb ◽  
E. Clément
Keyword(s):  
Granular Packing
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