N.A. Dumont, D. Huaman

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 111-112, 2011, DOI:10.3970/icces.2011.019.111

Abstract This paper proposes a hybrid finite element formulation of the strain gradient elasticity that provides a natural conceptual framework to properly deal with the interelement compatibility of normal displacement gradients and the equilibrium of non-classical boundary forces. It is based on developments firstly proposed by Mindlin and further elaborated by Aifantis. Consistency is assessed - in the full manuscript version - by means of several generalized patch tests. More >

Y. Senda, M. Fujio, S. Shimamura, J. Blomqvist, R. M Nieminen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 93-94, 2011, DOI:10.3970/icces.2011.018.093

Abstract Atomistic molecular dynamics simulation for"polymer melts has been performed inten-sively and revealed the dynamical behavior of atomistic"chain structure in the melt. These atomistic"calculations, however, have been limited by the massive computational costs because of macroscopic properties of long chain polymer. It would be highly de-sirable to use a multiscale approach covering atomistic and macroscopic behavior of the polymer melt. We have developed computational method coupling atomic model and continuum model [1] and applied the method to polymer melt consisted of the long chain polymers. The polymer molecule is coarse-grained into meso-scopic model by so-called spring- More >

T. Watanabe, T.Gotoh

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 91-92, 2011, DOI:10.3970/icces.2011.018.091

Abstract The effects of polymer additives on decaying isotropic turbulence were numerically investigated using a hybrid approach. The approach consisted of a Brownian dynamics simulation with an enormous number of dumbbells and a turbulence DNS with large-scale parallel computations. A reduction of the energy dissipation rate and modification of the kinetic energy spectrum were observed when the reactions of the polymers were incorporated into the fluid motion. We found that results with few polymers and large replicas could approximate those with many polymers and smaller replicas as far as the large-scale statistics were concerned. More >

Paulo M. Pimenta

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 85-86, 2011, DOI:10.3970/icces.2011.017.085

Abstract This work addresses the development of some alternative hybrid and mixed variational formulations for the geometrically-exact three-dimensional first-order-shear shell boundary value problem [1,2]. In the framework of the complementary-energy-based formulations, a Legendre transformation is used to introduce the complementary energy density in the variational statements as a function of the cross-sectional resultants only. The corresponding variational principles are shown to feature stationarity within the framework of the boundary-value-problem. The main features of the principles are highlighted, giving special attention to their relationships from both theoretical and numerical point of view.

Variational principles constitute the core… More >

Ravi Pandey

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 31-32, 2011, DOI:10.3970/icces.2011.020.031

Abstract Theme Lecture: First Principles Study of Nano-bio Hybrid Systems
Prof Ravi Pandey
Michigan Tech University, USA More >

Nobuko Ohba, Shuji Ogata

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 77-78, 2011, DOI:10.3970/icces.2011.019.077

Abstract We have been developing the concurrent-type, hybrid quantum-classical simulation scheme for various atomic processes at liquid-solid interfaces [1]. In this scheme, the density-functional theory (DFT) method is applied to the "quantum" region to calculate the electronic structure; while the semi-empirical inter-atomic potential, to the "classical" region. In this talk we review its recent developments both from methodology and application viewpoints.
In the hybrid simulation, the DFT method that is applied at each time-step to a cluster of typically a hundred atoms (i.e., the QM region) consumes most of the computation power. It is highly desirable… More >

De-Shin Liu, Zhen-Wei Zhuang, Cho-Liang Chung

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.019.039

Abstract A two-dimensional heterogeneous hybrid moisture element method (HHMEM) for modeling transient moisture diffusion in permeable fiber-reinforced polymer composites is proposed in this paper.
The HHMEM scheme is based on a heterogeneous hybrid moisture element (HHME), whose properties are determined by equivalent moisture capacitance and conductance matrixes calculated using the conventional finite element formulation with the similarity mass/stiffness property and matrix condensing operations. A coupled HHME-FE scheme is developed and implemented in computer codes MATLAB to analyze the transient moisture diffusion characteristics of polymeric composite materials containing multiple permeable fibers. The analysis commences by comparing the… More >

De-Shin Liu¹, Zhen-Wei Zhuang¹, Shaw-Ruey Lyu^2,3, Cho-Liang Chung⁴, Pai-Chen Lin¹

CMC-Computers, Materials & Continua, Vol.26, No.2, pp. 111-136, 2011, DOI:10.3970/cmc.2011.026.111

Abstract This study proposes a two-dimensional heterogeneous hybrid moisture element method (HHMEM) for modeling transient moisture diffusion in permeable fiber-reinforced polymer composites.
The HHMEM scheme is based on a heterogeneous hybrid moisture element(HHME), with properties determined through an equivalent hybrid moisture capacitance/conductance matrix. This matrix was calculated using the conventional finite element formulation in space discretization as well as the θ-method in time discretization with similar mass/stiffness properties and matrix condensing operations. A coupled HHME-FE scheme was developed and implemented in computer code MATLAB in order to analyze the transient moisture diffusion characteristics of composite materials containing multiple… More >

N. Ohba^1,2, S. Ogata², T. Tamura², S. Yamakawa¹, R. Asahi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.75, No.3&4, pp. 247-266, 2011, DOI:10.3970/cmes.2011.075.247

Abstract Understanding the stress dependence of Li diffusivity in the Li-graphite intercalation compound (Li-GIC) that has been used in the Li-ion rechargeable battery as a negative electrode, is important to search for better conditions to improve the power performance of the battery. In the Li-GIC, the Li ion creates a long-ranged stress field around itself by expanding the inter-layer distance of the graphite. To take into account such a long-ranged stress field in the first-principles simulation of the Li diffusion, we develop the hybrid quantum (QM)-classical (CL) simulation code. In the hybrid code, the QM region… More >

F. Tan^1,2, Y.L. Zhang¹, Y.H. Wang³, Y. Miao³

CMES-Computer Modeling in Engineering & Sciences, Vol.75, No.1, pp. 1-32, 2011, DOI:10.3970/cmes.2011.075.001

Abstract The meshless hybrid boundary node method (HBNM) for solving the bending problem of the Kirchhoff thin plate is presented and discussed in the present paper. In this method, the solution is divided into two parts, i.e. the complementary solution and the particular solution. The particular solution is approximated by the radial basis function (RBF) via dual reciprocity method (DRM), while the complementary one is solved by means of HBNM. The discrete equations of HBNM are obtained from a variational principle using a modified hybrid functional, in which the independent variables are the generalized displacements and… More >