Effective Properties of Ferromagnetic Composites

Author(s):  
Andrei A. Snarskii ◽  
Igor V. Bezsudnov ◽  
Vladimir A. Sevryukov ◽  
Alexander Morozovskiy ◽  
Joseph Malinsky
Keyword(s):  
2010 ◽  
Vol 38 (4) ◽  
pp. 286-307
Author(s):  
Carey F. Childers

Abstract Tires are fabricated using single ply fiber reinforced composite materials, which consist of a set of aligned stiff fibers of steel material embedded in a softer matrix of rubber material. The main goal is to develop a mathematical model to determine the local stress and strain fields for this isotropic fiber and matrix separated by a linearly graded transition zone. This model will then yield expressions for the internal stress and strain fields surrounding a single fiber. The fields will be obtained when radial, axial, and shear loads are applied. The composite is then homogenized to determine its effective mechanical properties—elastic moduli, Poisson ratios, and shear moduli. The model allows for analysis of how composites interact in order to design composites which gain full advantage of their properties.


Technologies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 12
Author(s):  
Federico J. Sabina ◽  
Yoanh Espinosa-Almeyda ◽  
Raúl Guinovart-Díaz ◽  
Reinaldo Rodríguez-Ramos ◽  
Héctor Camacho-Montes

The development of micromechanical models to predict the effective properties of multiphase composites is important for the design and optimization of new materials, as well as to improve our understanding about the structure–properties relationship. In this work, the two-scale asymptotic homogenization method (AHM) is implemented to calculate the out-of-plane effective complex-value properties of periodic three-phase elastic fiber-reinforced composites (FRCs) with parallelogram unit cells. Matrix and inclusions materials have complex-valued properties. Closed analytical expressions for the local problems and the out-of-plane shear effective coefficients are given. The solution of the homogenized local problems is found using potential theory. Numerical results are reported and comparisons with data reported in the literature are shown. Good agreements are obtained. In addition, the effects of fiber volume fractions and spatial fiber distribution on the complex effective elastic properties are analyzed. An analysis of the shear effective properties enhancement is also studied for three-phase FRCs.


Meccanica ◽  
2021 ◽  
Author(s):  
J. Jansson ◽  
K. Salomonsson ◽  
J. Olofsson

AbstractIn this paper we present a semi-multiscale methodology, where a micrograph is split into multiple independent numerical model subdomains. The purpose of this approach is to enable a controlled reduction in model fidelity at the microscale, while providing more detailed material data for component level- or more advanced finite element models. The effective anisotropic elastic properties of each subdomain are computed using periodic boundary conditions, and are subsequently mapped back to a reduced mesh of the original micrograph. Alternatively, effective isotropic properties are generated using a semi-analytical method, based on averaged Hashin–Shtrikman bounds with fractions determined via pixel summation. The chosen discretization strategy (pixelwise or partially smoothed) is shown to introduce an uncertainty in effective properties lower than 2% for the edge-case of a finite plate containing a circular hole. The methodology is applied to a aluminium alloy micrograph. It is shown that the number of elements in the aluminium model can be reduced by $$99.89\%$$ 99.89 % while not deviating from the reference model effective material properties by more than $$0.65\%$$ 0.65 % , while also retaining some of the characteristics of the stress-field. The computational time of the semi-analytical method is shown to be several orders of magnitude lower than the numerical one.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 925
Author(s):  
Diogo Heitor ◽  
Isabel Duarte ◽  
João Dias-de-Oliveira

X-ray microcomputed tomography has been gaining relevance in the field of cellular materials to characterize materials and analyse their microstructure. So, here, it was used together with finite element modelling to develop numerical models to estimate the effective properties (Young’s modulus) of aluminium alloy foams and evaluate the effects of processing on the results. A manual global thresholding technique using the mass as a quality indicator was used. The models were reconstructed (Marching Cubes 33), then simplified and analysed in terms of mass and shape maintenance (Hausdorff distance algorithm) and face quality. Two simplification procedures were evaluated, with and without small structural imperfections, to evaluate the impact of the procedures on the results. Results demonstrate that the developed procedures are good at minimizing changes in mass and shape of the geometries while providing good face quality, i.e., face aspect ratio. The models are also shown to be able to predict the effective properties of metallic foams in accordance with the findings of other researchers. In addition, the process of obtaining the models and the presence of small structural imperfections were shown to have a great impact on the results.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 518
Author(s):  
N. Suresh Kumar ◽  
K. Chandra Babu Naidu ◽  
Prasun Banerjee ◽  
T. Anil Babu ◽  
B. Venkata Shiva Reddy

Metamaterials are the major type of artificially engineered materials which exhibit naturally unobtainable properties according to how their microarchitectures are engineered. Owing to their unique and controllable effective properties, including electric permittivity and magnetic permeability, the metamaterials play a vital role in the development of meta-devices. Therefore, the recent research has mainly focused on shifting towards achieving tunable, switchable, nonlinear, and sensing functionalities. In this review, we summarize the recent progress in terahertz, microwave electromagnetic, and photonic metamaterials, and their applications. The review also encompasses the role of metamaterials in the advancement of microwave sensors, photonic devices, antennas, energy harvesting, and superconducting quantum interference devices (SQUIDs).


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4676
Author(s):  
Jorge Luis Costafreda ◽  
Domingo Alfonso Martín

This work describes the newly discovered zeolites in the eastern region of Cuba. In the researched area, there have been no previous studies of natural zeolite exploration. Therefore, the results shown here are new. The main object of this research is to analyse five samples of zeolites and demonstrate their pozzolanic capacity and the possibility of their usage in the industrial manufacturing of pozzolanic cements. The study of the samples was performed by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). A chemical analysis (CAQ) to determine the quality of the samples as pozzolans was performed, by determining the total SiO2, reactive SiO2, total CaO, reactive CaO, Al2O3, MgO and the insoluble residue (I.R.). Lastly, an eight-day pozzolanicity analysis (PA) was carried out to determine the pozzolanic reactivity of the samples. The results obtained by XRD, XRF and SEM established that the researched zeolite samples have two main zeolitic phases: mordenite and clinoptilolite. Altered volcanic glass, quartz and smectite (montmorillonite) are the secondary phases. The results of the chemical quality analysis (CAQ) showed that the samples contain a considerable amount of reactive SiO2 and reactive CaO, as well as a low content of insoluble residue, which reinforces their properties as pozzolans. The results of the pozzolanicity analysis (PA) concluded that the analysed samples actively react with Ca(OH)2 after eight days. Based on all the results mentioned above, it is established that both mordenite and clinoptilolite behave like pozzolans and can be recommended for the manufacture of pozzolanic cements, which have more effective properties than Portland cement, in terms of physical, chemical and mechanical strength, low heat of hydration, resistance to sulphates, low CO2 emissions to the atmosphere and negligible impacts on the environment.


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