A topology optimization approach used to assess the effect of the matrix impregnation on the effective elastic properties of a unidirectional carbon nanotube bundle composite

In this study, a finite element model of a representative volume element that contains a hollow and filled single-walled Carbon nanotube (SWCNT) in two case studies was generated. It was assumed that the nanocomposites have geometric periodicity with respect to local length scale and the elastic properties can be represented by those of the representative volume element (RVE). Elastic properties in agreement with existing literature values for the Carbon nanotube and the matrix were assigned. Then for the two case studies, the tensile test was simulated to find the effect of the geometry, i.e. the volume fraction of matrix and SWCNT's properties variation, on the effective Young's modulus of the structure. In another approach, by applying perpendicular loading to the tube direction, the effect of matrix volume fraction on the transverse Young's modulus was studied. The investigations showed that for both RVEs with filled SWCNT and hollow SWCNT, the effective Young's modulus of the structure decreases approximately linear as the matrix volume fraction increases. The value of Young's modulus of the RVE with a filled Carbon nanotube was obtained to be higher than the RVE with the hollow Carbon nanotube. In addition, by increasing the tube diameter, the effective Young's modulus of the structure increases and the transverse Young's modulus decreases approximately linear for filled tubes but this parameter remains rather constant in the case of the hollow tube by increasing the matrix volume fraction.

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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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Multi-stage micromechanical modeling of effective elastic properties of carbon fiber/carbon nanotube-reinforced polymer hybrid composites

Mechanics of Advanced Materials and Structures ◽

10.1080/15376494.2018.1472336 ◽

2018 ◽

Vol 26 (24) ◽

pp. 2047-2061 ◽

Cited By ~ 12

Author(s):

Mohammad-Kazem Hassanzadeh-Aghdam ◽

R. Ansari ◽

Abolfazl Darvizeh

Keyword(s):

Carbon Nanotube ◽

Carbon Fiber ◽

Elastic Properties ◽

Hybrid Composites ◽

Micromechanical Modeling ◽

Effective Elastic Properties ◽

Polymer Hybrid ◽

Reinforced Polymer ◽

Multi Stage

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Effect of the Orientation of Hexagonal Fibers on the Effective Elastic Properties of Unidirectional Composites

Journal of Mechanics ◽

10.1017/jmech.2016.109 ◽

2016 ◽

Vol 34 (3) ◽

pp. 257-267 ◽

Cited By ~ 2

Author(s):

H. Wang ◽

Y.-X. Kang ◽

B. Liu ◽

Q.-H. Qin

Keyword(s):

Elastic Properties ◽

Matrix Material ◽

Unidirectional Composite ◽

Element Analysis ◽

Effective Elastic Properties ◽

Displacement Boundary ◽

Straight Line ◽

The Matrix ◽

Homogenization Approach

AbstractExisting studies reveal that the shape corners of hexagonal fiber affect the degree of constraint on the matrix material. However, none of these studies included the effect of orientation of hexagonal fibers. In this study, a computational micromechanics model of oriented hexagonal fibers in periodic unidirectional composite materials is established for the determination of effective orthotropic elastic properties of the composite. In the present numerical modeling, the representative unit composite cell including the matrix material and the single oriented hexagonal fiber or random oriented hexagonal fibers is solved by micro-scale finite element analysis with different stress loads and periodic displacement boundary conditions, which are applied along the cell boundary to meet the requirement of straight-line constraint during deformation of the cell. Subsequently, the effective elastic properties of the composite are evaluated for periodic regular packing and random packing using the homogenization approach for investigating the influence of unified orientation and random orientation of the hexagonal fibers on the overall elastic properties of the fiber-reinforced composites. The numerical results are verified by comparing with other available results.

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