Zhenguo Tu¹, Fuxing Miao¹, Guojun Sun¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.4, pp. 125-130, 2007, DOI:10.3970/icces.2007.002.125

Abstract In this paper the reverberation ray matrix method, which was developed recently by Professor Pao and his colleagues for analyzing dynamic response of elastic trusses or frames, is extended and used to solve the transient response of frames made of viscoelastic bars. Originally for the solution of elastic structure the matrix (I-R)-1 is expanded into Neumann series to circumvent the difficulty of singularity in reversing the matrix in frequency domain. However, it is not necessary to expand this matrix since there is no singularity problem for viscoelastic frame due to viscous damping. The accuracy and More >

Chein-Shan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.3, pp. 157-176, 2007, DOI:10.3970/cmes.2007.020.157

Abstract In many engineering applications the Lie group calculation is very important. With this in mind, the subject of this paper is for an in-depth investigation of time-varying linear systems, and its accompanied Lie group calculations. In terms of system matrix A in Eq. (11) and a one-order lower fundamental solution matrix associated with the sub-state matrix function A_s^s, we propose two methods to nilpotentlize the time-varying linear systems. As a consequence, we obtain two different calculations of the general linear group. Then, the nilpotent systems are further transformed to a unique new system Ż(t) = B(t)Z(t), which More >

Weiran Yuan¹, Pu Chen^1,2, Kaishin Liu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.2, pp. 115-134, 2007, DOI:10.3970/cmes.2007.017.115

Abstract In this paper we propose a direct solution method for the quasi-unsymmetric sparse matrix (QUSM) arising in the Meshless Local Petrov-Galerkin method (MLPG). QUSM, which is conventionally treated as a general unsymmetric matrix, is unsymmetric in its numerical values, but nearly symmetric in its nonzero distribution of upper and lower triangular portions. MLPG employs trial and test functions in different functional spaces in the local domain weak form of governing equations. Consequently the stiffness matrix of the resultant linear system is a QUSM. The new solver for QUSM conducts a two-level unrolling technique for LDU factorization More >

X. E. Guo¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 183-184, 2006, DOI:10.32604/mcb.2006.003.183

Abstract This article has no abstract. More >

E. Takai¹, R. Landesberg², R.W. Katz², C.T. Hung³, X.E Guo^1,4

Molecular & Cellular Biomechanics, Vol.3, No.1, pp. 1-12, 2006, DOI:10.3970/mcb.2006.003.001

Abstract Osteoblast interactions with extracellular matrix (ECM) proteins are known to influence many cell functions, which may ultimately affect osseointegration of implants with the host bone tissue. Some adhesion-mediated events include activation of focal adhesion kinase, and subsequent changes in the cytoskeleton and cell morphology, which may lead to changes in adhesion strength and cell responsiveness to mechanical stimuli. In this study we examined focal adhesion kinase activation (FAK), F-actin cytoskeleton reorganization, adhesion strength, and osteoblast responsiveness to fluid shear when adhered to type I collagen (ColI), glass, poly-L-lysine (PLL), fibronectin (FN), vitronectin (VN), and serum… More >

Chein-Shan Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.3, pp. 157-176, 2006, DOI:10.3970/cmes.2006.016.157

Abstract To characterize largely deformed spin-free reference configuration of materials, we have to construct an orthogonal transformation tensor Q relative to the fixed frame, such that the tensorial equation Q^˙ = WQ holds for a given spin history W. This paper addresses some interesting issues about this equation. The Euler's angles representation, and the (modified) Rodrigues parameters representation of the rotation group SO(3) unavoidably suffer certain singularity, and at the same time the governing equations are nonlinear three-dimensional ODEs. A decomposition Q = FQ₁ is first derived here, which is amenable to a simpler treatment of Q₁ than Q, and… More >

F. Han¹, E. Pan¹, A.K. Roy², Z.Q. Yue³

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.1, pp. 15-30, 2006, DOI:10.3970/cmes.2006.014.015

Abstract In this paper, an analytical solution is presented to study the response of piezoelectric, transversely isotropic, functionally graded, and multilayered half spaces to uniform circular surface loadings (pressure or negative electric charge). The inhomogeneous material is exponentially graded in the vertical direction and can have multiple discrete layers. The propagator matrix method and cylindrical system of vector functions are used to first derive the solution in the transformed domain. In order to find the responses in the physical-domain, which are expressed in one-dimensional infinite integrals of the Bessel function products, we introduced and adopted an… 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 >

Y.F. Nie^1,2, S.N. Atluri², C.W. Zuo¹

CMES-Computer Modeling in Engineering & Sciences, Vol.12, No.2, pp. 137-148, 2006, DOI:10.3970/cmes.2006.012.137

Abstract Owing to the meshless and local characteristics, moving least squares (MLS) methods have been used extensively to approximate the unknown function of partial differential equation initial boundary value problem. In this paper, based on matrix analysis, a sufficient and necessary condition for the existence of inverse of coefficient matrix used in MLS methods is developed firstly. Then in the light of approximate theory, a practical mathematics model is posed to obtain the optimal radius of support of radial weights used in MLS methods. As an example, while uniform distributed particles and the 4^th order spline weight More >

S. Marguet¹, P. Rozycki¹, L. Gornet¹

CMC-Computers, Materials & Continua, Vol.4, No.3, pp. 119-136, 2006, DOI:10.3970/cmc.2006.004.119

Abstract This paper deals with the modelling until rupture of composite structures made of glass-fibre / epoxy-resin woven fabrics submitted to dynamic loadings. The model is built at the mesoscale of the elementary ply. It takes into account the slightly nonlinear brittle behaviour of the fibres under tensile sollicitations, their nonlinear behaviour in compression as well as the strongly non linear and irreversible behaviour of the ply in shear. Strain rate effects are also introduced and special attention is paid to the objectivity of the model in the context of finite element calculation. Therefore the choice… More >