Shasha Yang¹, Shuling Hu¹, Shengping Shen^1,2

CMC-Computers, Materials & Continua, Vol.29, No.3, pp. 279-298, 2012, DOI:10.3970/cmc.2012.029.279

Abstract Due to the large ratio of surface area to volume in nanoscale objects, the property of surfaces and interfaces likely becomes a prominent factor in controlling the behavior of nano-heterogeneous materials. In this work, based on the Gurtin-Murdoch surface/interface elastic theory, a distinct expression is derived for embedded nano-inclusion in an infinite piezoelectric matrix coupled with interface effect. For the problem of a spherical inclusion in transversely isotropic piezoelectric medium, we reach a conclusion that the elastic and electric field are uniform when eigen-strain and eigen-electric field imposed on the inclusion are uniform even in More >

J. Zidek^1,2, J. Kucera¹, J. Jancar^1,2

CMC-Computers, Materials & Continua, Vol.28, No.3, pp. 213-230, 2012, DOI:10.3970/cmc.2012.028.213

Abstract The paper presents a combination of worm-like chain numerical models and one with a finite set of nano-particles. The primary objective of the models was to analyze the distribution of space in a system filled by particles. Information on the distribution of space was compared to properties of chains inside the set of particles. The set of nanoparticles was constructed with a tool generating a finite set of particles that is randomly distributed in a given space. The particles have a prescribed volume fraction and uniform size. First, the proportions of chains and particles were… More >

R. Khanna^1,2, D. R. Katti¹, K. S. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 530-556, 2012, DOI:10.3970/cmes.2012.087.530

Abstract Here we report a new in situ nanoindentation technique developed to evaluate the composite mechanical behavior of cell-biomaterial construct under physiological conditions over the time scale of bone nodule generation. Using this technique, mechanical behavior of osteoblast cell-substrate interfaces on tissue engineered materials (chitosan-polygalacturonic acid-nanohydroxyapatite (CPH) films) is investigated. Mechanical behavior of cells in the elastic regime over the time scale of cell adhesion (1 day), proliferation (4 days), development (8 days) and maturation (22 days) of bone nodules is evaluated. Our results indicate that the elastic properties of flat cells are higher (indicating stiffer… More >

Alamusi, Yaolu Liu, Ning Hu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 57-58, 2011, DOI:10.3970/icces.2011.016.057

Abstract In this work, we propose a 3 dimensional (3D) numerical model to predict the piezoresistivity behaviours of a nanocomposite material made from an insulating polymer filled by carbon nanotubes (CNTs). This material is very hopeful for its application in highly sensitive strain sensor by measuring its piezoresistivity, i.e., the ratio of resistance change versus applied strain. In this numerical approach, a 3D resistor network model is firstly proposed to predict the electrical conductivity of the nanocomposite with a large amount of randomly dispersed CNTs under the zero strain state. By focusing on the fact that… More >

Surkay D. Akbarov^1,2, Resat Kosker³, Nihan T. Cinar³

CMC-Computers, Materials & Continua, Vol.21, No.2, pp. 119-146, 2011, DOI:10.3970/cmc.2011.021.119

Abstract In the present paper, the stress distribution in an infinite elastic body containing two neighboring nanofibers is studied. It is assumed that the midlines of the fibers are in the same plane. With respect to the location of the fibers according to each other the co-phase and anti-phase curving cases are considered. At infinity uniformly distributed normal forces act in the direction of the nanofibers, location. The investigations are carried out in the framework of the piecewise homogeneous body model with the use of the three-dimensional geometrically non-linear exact equations of the theory of elasticity. More >

R. J. Johnson^∗, R. Pitchumani^†

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-9, 2010, DOI:10.5098/hmt.v1.1.3007

Abstract Much research is currently being performed with carbon nanotube additives to neat resin systems to enhance properties such as thermal and electrical conductivity, strength, modulus and damping. Fabrication of parts based on carbon nanotube filled resin systems requires information on their cure kinetics and rheology, which has been relatively less studied so far. This work presents an extensive experimental study that systematically characterizes the cure kinetics and viscosity as a function of degree of cure and temperature of EPON 815C/EPICURE 3274 epoxy resin system laden with carbon nanotubes. Studies are conducted to determine the effects More >

G.I. Giannopoulos¹, S.K. Georgantzinos², D.E. Katsareas², N.K. Anifantis²

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.3, pp. 231-248, 2010, DOI:10.3970/cmes.2010.056.231

Abstract A hybrid finite element formulation, combining nanoscopic and macroscopic considerations is proposed, for the prediction of the elastic mechanical properties of single walled carbon nanotube (SWCNT)-based composites. The nanotubes are modeled according to the molecular mechanics theory via the use of spring elements, while the matrix is modeled as a continuum medium. A new formulation concerning the load transfer between the nanotubes and matrix is proposed. The interactions between the two phases are implemented by utilizing appropriate stiffness variations describing a heterogeneous interfacial region. A periodic distribution and orientation of the SWCNTs is considered. Thereupon, More >

Alamusi¹, Y.L. Liu¹, N. Hu^1,2

CMC-Computers, Materials & Continua, Vol.20, No.2, pp. 101-118, 2010, DOI:10.3970/cmc.2010.020.101

Abstract In this work, we propose a 3 dimensional (3D) numerical model to predict the piezoresistivity behaviors of a nanocomposite material made from an insulating polymer filled by carbon nanotubes (CNTs). This material is very hopeful for its application in highly sensitive strain sensor by measuring its piezoresistivity, i.e., the ratio of resistance change versus applied strain. In this numerical approach, a 3D resistor network model is firstly proposed to predict the electrical conductivity of the nanocomposite with a large amount of randomly dispersed CNTs under the zero strain state. By focusing on the fact that… More >

Hui- Shen^1,2, Zheng Hong Zhu³

CMC-Computers, Materials & Continua, Vol.18, No.2, pp. 155-182, 2010, DOI:10.3970/cmc.2010.018.155

Abstract This paper investigates the buckling and postbuckling of simply supported, nanocomposite plates with functionally graded nanotube reinforcements subjected to uniaxial compression in thermal environments. The nanocomposite plates are assumed to be functionally graded in the thickness direction using single-walled carbon nanotubes (SWCNTs) serving as reinforcements and the plates' effective material properties are estimated through a micromechanical model. The higher order shear deformation plate theory with a von Kármán-type of kinematic nonlinearity is used to model the composite plates and a two-step perturbation technique is performed to determine the buckling loads and postbuckling equilibrium paths. Numerical… More >

J. Wang¹, D. C. C. Lam²

CMC-Computers, Materials & Continua, Vol.17, No.3, pp. 215-232, 2010, DOI:10.3970/cmc.2010.017.215

Abstract Selected elastic moduli of nanocomposites are higher than the elastic moduli of microcomposites. Molecular immobilization and crystallization at the interfaces had been proposed as potential causes, but studies suggested that these effects are minor and cannot be used to explain the magnitude observed in nanocomposites with >3nm particles. Alternately, molecular simulation of polymer deformation showed that rotation gradients can lead to additional molecular rotations and stiffen the matrix. The stiffening is characterized by the nanostiffening material parameter, l2. In this investigation, an analytical expression for nanostiffening in nanocomposites was developed using finite element analysis. The More >