A.N. Guz¹, J.J.Rushchitsky¹, I.A.Guz²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 139-156, 2008, DOI:10.3970/cmes.2008.026.139

Abstract The basic approach is offered for problems of nanocomposites and their mechanical properties, which includes a short review of modern problems in nanomechanics of materials. The fibrous carbon-polymer composites with carbon or graphite microfibers or carbon nanotubes are especially discussed. The basic model of the linear or nonlinear elastically deforming micro- and nanocomposites is considered. Within the framework of this model, the comparative computer modeling is performed. The modeling permits to observe the features in prediction of values of basic mechanical constants. These results are utilized on next step of modeling -- studying the peculiarities of wave propagation in particular… More >

A. N. Guz, V. A. Dekret¹

CMES-Computer Modeling in Engineering & Sciences, Vol.13, No.3, pp. 165-170, 2006, DOI:10.3970/cmes.2006.013.165

Abstract Stability problem of composite material reinforced by two parallel short fibers is solved. The problem is formulated with application of equations of linearized three-dimensional theory of stability. The composite is modeled as piecewise-homogeneous medium. The influence of geometrical and mechanical parameters of the material on critical strain is investigated. More >

T. Ishizawa¹, M. Iura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.3, pp. 121-130, 2006, DOI:10.3970/cmes.2006.011.121

Abstract A one-dimensional model is proposed for numerical analysis of partially concrete-filled steel tubular (PCFST) columns subjected to cyclic loadings. The present formulation does not require experimental results nor shell analysis to obtain the constitutive equation of the model. The material properties and dimensions of PCFST columns are required for numerical analysis of the present model. The PCFST columns are assumed to consist of elastic beam and base plastic-hinge region in which steel local buckling is observed. Two parameters are introduced in order to express hardening phenomena of PCFST columns subjected to cyclic loading. Resisting forces due to concrete filled in… More >

D. Bergmair^1,2, S. J. Metz¹, H. C. de Lange², A. A. van Steenhoven²

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.1, pp. 1-15, 2013, DOI:10.3970/cmes.2013.091.001

Abstract A method to predict the permeation of water vapor, present in a laminar flowing humid carrier gas, through a hollow fiber membrane is presented. The method uses simulation particles that move like molecules, according to the kinetic gas theory, but carry the physical properties of an ensemble of molecules which they statistically represent. With this approach an ideal operational window for membrane modules can be found and parameters tested for, can be varied over orders of magnitude. The results show that the right dimensioning is essential for the efficient use of the membrane area. More >

Sheng Yan Li¹, Bin Gang Xu^1,2, Xiao Ming Tao¹, Hong Hu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.1, pp. 33-56, 2011, DOI:10.3970/cmes.2011.077.033

Abstract Slender yarn structure made from natural fibers, nano-fibers, carbon nanotubes or other types of fibrous materials is all formed by twisting an assembly of short or long fibers and its performance is significantly influenced by the physical behavior of these fibers in the slender yarn forming region - a small triangle area called spinning triangle. In this paper, a new generalized FEM model of spinning triangle has been developed to theoretically analyze the fiber structural and mechanical performance in fabrication of these slender yarn structures. In this proposed model, a geometrical model of spinning triangle is developed and the initial… More >

Binxin Yang¹, Jie Ouyang¹, Tao Jiang¹, Chuntai Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.3, pp. 191-222, 2010, DOI:10.3970/cmes.2010.063.191

Abstract A gas-solid-liquid three-phase model is proposed for fiber reinforced composites mold filling process. The fluid flow is described in Eulerian coordinate while the dynamics of fibers is described in Langrangian coordinate. The interaction of fluid flow and fibers are enclosed in the model. The influence of fluid flow on fibers is described by the resultant forces imposed on fibers and the influence of fibers on fluid flow is described by the momentum exchange source term in the model. A finite volume method coupled with a level set method for viscoelastic-Newtonian fluid flow is used to solve the model. The direct… More >

Hui-Fen Guo^1,2, Bin-Gang Xu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.61, No.3, pp. 201-222, 2010, DOI:10.3970/cmes.2010.061.201

Abstract A numerical method is developed for modeling the dynamics of a flexible fiber immersed in a compressible swirling flow. The modeling approach is based on combining an Eulerian finite volume formulation for the fluid flow and a Lagrangian small-deformation formulation for the dynamics of the fiber. The fiber is modeled as a chain of beads connected through mass-less rods. The bending and twisting deformation of the fiber are represented by the displacements of the successive beads. A computational strategy is proposed for the computation of the fluid parameters at the center of discrete fiber sections. To deal with the fiber-wall… More >

B.Y. Lee¹, Y. Lee², J.K.Kim³, Y.Y.Kim⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.61, No.2, pp. 111-132, 2010, DOI:10.3970/cmes.2010.061.111

Abstract In the present work, a micromechanics-based fiber-bridging constitutive model that quantitatively takes into consideration the distribution of fiber orientation and the number of fibers, is derived and a fiber-bridging analysis program is developed. An image processing technique is applied to evaluate the fiber distribution characteristics of four different types of strain-hardening cementitious composites. Then, the fiber-bridging curves obtained from image analysis are compared with those obtained from the assumption of two- and three-dimensional fiber distributions. The calculated ultimate tensile strains are also compared with experimental results. Test results showed that the tensile behavior of strain-hardening cementitious composites can be more… More >

A.N. Guz, V.A. Dekret¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.1, pp. 69-80, 2009, DOI:10.3970/cmes.2009.049.069

Abstract The two models in the three-dimensional theory of stability of the nanotube reinforced composite materials are discussed. The model of "infinite fibers" and the model of "short fibers" are considered. The primary objective is attended to "short fibers" model. All results are obtained in the framework of the three-dimensional linearized theory of stability of deformable bodies. More >

Eugenio Brusa¹, Matteo Nobile²

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.2, pp. 155-190, 2009, DOI:10.3970/cmes.2009.048.155

Abstract Lightness of high pressure vessels is currently assured by composite materials. Construction of over-wrapped composite pressure vessels with inner metallic liner is for instance compatible with standards requirements of the hydrogen technology of energy storage. Therefore a typical layout manufactured by some industries consists of a cylindrical vessel with covering of carbon-epoxy laminates and metallic impermeable liner. To allow the filament winding of the composite fibres are used hoop and helical layers, respectively. A single nozzle is usually built. It requires that the vessel material is reinforced. This need imposes to have a variable thickness in the composite layer. In… More >