Predicting the properties of micro- and nanocomposites: from the microwhiskers to the bristled nano-centipedes

The paper draws on the similarities between the well-known process of whiskerization of microfibres and the recent idea of bristled nanowires. The new method for evaluation of the effective elastic properties of such materials is suggested based on the model of four-component composition. This model assumes the transverse isotropy of continuum and predicts five elastic moduli and density as independent effective constants. An example of calculation of the constants for the particular materials is given. It shows the significant increase in the shear strength of composites with whiskerized or bristled fibres.

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Modeling of the Effective Elastic Properties of Multifunctional Carbon Nanocomposites Due to Agglomeration of Straight Circular Carbon Nanotubes in a Polymer Matrix

Journal of Applied Mechanics ◽

10.1115/1.4024414 ◽

2013 ◽

Vol 81 (2) ◽

Cited By ~ 8

Author(s):

Chetan Shivaputra Jarali ◽

Somaraddi R. Basavaraddi ◽

Björn Kiefer ◽

Sharanabasava C. Pilli ◽

Y. Charles Lu

Keyword(s):

Carbon Nanotubes ◽

Elastic Properties ◽

Elastic Moduli ◽

Volume Fraction ◽

Effective Properties ◽

Transverse Isotropy ◽

Effective Elastic Moduli ◽

Effective Elastic Properties ◽

The Matrix ◽

Nanotube Composites

In the present study, the effective elastic properties of multifunctional carbon nanotube composites are derived due to the agglomeration of straight circular carbon nanotubes dispersed in soft polymer matrices. The agglomeration of CNTs is common due to the size of nanotubes, which is at nanoscales. Furthermore, it has been proved that straight circular CNTs provide higher stiffness and elastic properties than any other shape of the nanofibers. Therefore, in the present study, the agglomeration effect on the effective elastic moduli of the CNT polymer nanocomposites is investigated when circular CNTs are aligned straight as well as distributed randomly in the matrix. The Mori–Tanaka micromechanics theory is adopted to newly derive the expressions for the effective elastic moduli of the CNT composites including the effect of agglomeration. In this direction, analytical expressions are developed to establish the volume fraction relationships for the agglomeration regions with high, and dilute CNT concentrations. The volume of the matrix in which there may not be any CNTs due to agglomeration is also included in the present formulation. The agglomeration volume fractions are subsequently adopted to develop the effective relations of the composites for transverse isotropy and isotropic straight CNTs. The validation of the modeling technique is assessed with results reported, and the variations in the effective properties for high and dilute agglomeration concentrations are investigated.

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Estimation of elastic moduli of mixed porous clay composites

Geophysics ◽

10.1190/1.3511351 ◽

2011 ◽

Vol 76 (1) ◽

pp. E9-E20 ◽

Cited By ~ 6

Author(s):

Erling Hugo Jensen ◽

Charlotte Faust Andersen ◽

Tor Arne Johansen

Keyword(s):

Experimental Data ◽

Elastic Properties ◽

Elastic Moduli ◽

Rock Physics ◽

Common Procedure ◽

Effective Elastic Properties ◽

Confining Pressures ◽

Physics Model ◽

Rock Physics Model ◽

The Individual

We have developed a procedure for estimating the effective elastic properties of various mixtures of smectite and kaolinite over a range of confining pressures, based on the individual effective elastic properties of pure porous smectite and kaolinite. Experimental data for the pure samples are used as input to various rock physics models, and the predictions are compared with experimental data for the mixed samples. We have evaluated three strategies for choosing the initial properties in various rock physics models: (1) input values have the same porosity, (2) input values have the same pressure, and (3) an average of (1) and (2). The best results are obtained when the elastic moduli of the two porous constituents are defined at the same pressure and when their volumetric fractions are adjusted based on different compaction rates with pressure. Furthermore, our strategy makes the modeling results less sensitive to the actual rock physics model. The method can help obtain the elastic properties of mixed unconsolidated clays as a function of mechanical compaction. The more common procedure for estimating effective elastic properties requires knowledge about volume fractions, elastic properties of individual constituents, and geometric details of the composition. However, these data are often uncertain, e.g., large variations in the mineral elastic properties of clays have been reported in the literature, which makes our procedure a viable alternative.

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Random Fiber Array Generation Considering Actual Noncircular Fibers with a Particle-Shape Library

Applied Sciences ◽

10.3390/app10165675 ◽

2020 ◽

Vol 10 (16) ◽

pp. 5675

Author(s):

Myeong-Seok Go ◽

Shin-Mu Park ◽

Do-Won Kim ◽

Do-Soon Hwang ◽

Jae Hyuk Lim

Keyword(s):

Elastic Properties ◽

Particle Shape ◽

Elastic Moduli ◽

Von Mises Stress ◽

Fiber Volume ◽

Fiber Array ◽

Effective Elastic Properties ◽

The Matrix ◽

Array Generation ◽

Von Mises

In this work, we generated a set of random representative volume elements (RVEs) of unidirectional composites considering actual noncircular cross-sections and positions of fibers with the aid of a shape-library approach. The cross-section of the noncircular carbon fiber was extracted from the M55J/M18 composite using image processing and a signed-distance-based mesh trimming scheme, and they were stored in a particle-shape library. The obtained noncircular fibers randomly chosen from the particle-shape library were applied to random fiber array generation algorithms to generate RVEs of various fiber volume fractions. To check the randomness of the proposed RVEs, we calculated spatial and physical metrics, and concluded that the proposed method is sufficiently random. Furthermore, to compare the effective elastic properties and the maximum von Mises stress in the matrix, it was applied to composite materials with different relative ratios of elastic moduli of M55J/M18 and T300/PR319. In the case of T300/PR319 having a high RRT (relative ratio of the transverse elastic moduli), simulation results were deviated up to about 5% in the effective elastic properties and 13% in the maximum von Mises stress in the matrix according to the fiber shapes.

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On the Mechanical Behavior of the Orthotropic Cord-Rubber Composite

Tire Science and Technology ◽

10.2346/1.2167223 ◽

1976 ◽

Vol 4 (4) ◽

pp. 219-232 ◽

Cited By ~ 2

Author(s):

Ö. Pósfalvi

Keyword(s):

Mechanical Behavior ◽

Uniaxial Tension ◽

Elastic Properties ◽

Large Deformations ◽

Virtual Work ◽

Poisson's Ratio ◽

Principle Of Virtual Work ◽

Effective Elastic Properties ◽

Rubber Composite ◽

Mooney Equation

Abstract The effective elastic properties of the cord-rubber composite are deduced from the principle of virtual work. Such a composite must be compliant in the noncord directions and therefore undergo large deformations. The Rivlin-Mooney equation is used to derive the effective Poisson's ratio and Young's modulus of the composite and as a basis for their measurement in uniaxial tension.

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