C.-D. Tran¹, N. Mai-Duy^1,1, K. Le-Cao¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.6, pp. 499-520, 2012, DOI:10.3970/cmes.2012.085.499

Abstract A numerical computation of continuum-microscopic model for visco-elastic flows based on the Integrated Radial Basis Function (IRBF) Control Volume and the Stochastic Simulation Techniques (SST) is reported in this paper. The macroscopic flow equations are closed by a stochastic equation for the extra stress at the microscopic level. The former are discretised by a 1D-IRBF-CV method while the latter is integrated with Euler explicit or Predictor-Corrector schemes. Modelling is very efficient as it is based on Cartesian grid, while the integrated RBF approach enhances both the stability of the procedure and the accuracy of the solution. The proposed method is… More >

M.M. Kamiński¹, J. Szafran¹

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.2, pp. 143-168, 2012, DOI:10.32604/cmes.2012.083.143

Abstract The main issue in this article is computational probabilistic analysis and reliability assessment of the steel telecommunication towers subjected to material and environmental uncertainty. Such a discussion is important since very wide, frequent and relatively modern application of these structures, which are subjected to various sources of uncertainty and having at this moment no rich and time-dependent failure evidence. Numerical analysis is based on the generalized stochastic perturbation technique implemented as the Stochastic Finite Elements using the Response Function Method applied with the use of computer algebra system. A simultaneous usage of the engineering FEM system and mathematical package enables… More >

C.-D. Tran¹, D.-A. An-Vo¹, N. Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.2, pp. 137-162, 2011, DOI:10.32604/cmes.2011.082.137

Abstract This paper presents a numerical approach for macro-micro multi-scale modelling of visco-elastic fluid flows based on the Integrated Radial Basis Function Networks (IRBFNs) and the Stochastic Simulation Technique (SST). The extra stress is calculated using the Brownian configuration fields (BCFs) technique while the velocity field is locally approximated at a set of collocation points using 1D-IRBFNs. In this approach, the stress is decoupled from the velocity field and computed from the molecular configuration directly without the need for a closed form rheological constitutive equation. The equations governing the macro flow field are discretised using a meshless collocation method where the… More >

Marcin Kamiński¹, Rafał Leszek Ossowski¹

CMES-Computer Modeling in Engineering & Sciences, Vol.81, No.3&4, pp. 311-334, 2011, DOI:10.3970/cmes.2011.081.311

Abstract The main aim of this article is numerical solution of the fully coupled Navier-Stokes equations with Gaussian random parameters. It is provided thanks to the specially adopted Finite Volume Method, modified using the generalized stochastic perturbation technique. This Stochastic Finite Volume Method is applied to model 3D problem with uncertainty in liquid viscosity and a coefficient of the heat conduction, separately. Probabilistic moments and characteristics of up to the fourth order are determined with the use of the Response Function Method realized numerically via the polynomial inpterpolation. Although mathematical formulation of the SFVM has been proposed in addition to the… More >

M.M. Kaminski

CMES-Computer Modeling in Engineering & Sciences, Vol.80, No.2, pp. 113-140, 2011, DOI:10.3970/cmes.2011.080.113

Abstract The main aim of this work is to demonstrate a solution to the transient problems for the statistically homogeneous media with random physical parameters. This is done with the use of the stochastic perturbation technique based on the general order Taylor series expansions and the additionally modified implementation of the Finite Element Method. Now, both the Direct Differentiation Method as well as the Response Function Method are employed to form and solve up to the nth order state equations. Computational implementation of both approaches is illustrated using two examples - by determination of the probabilistic moments of the temperature histories… More >

J.L. Sereno¹, J.C.F. Pereira¹

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.1, pp. 23-44, 2011, DOI:10.3970/cmes.2011.073.023

Abstract The evolution of a two-dimensional vortex pair in ground effect was studied under the influence of random initial inputs comprising vortex strength (circulation) or initial vortex position. The paper addresses the questions of how do variations and uncertainties of initial conditions translate to the variability of vortex pair evolution. The stochastic solutions were obtained recurring to the Polynomial Chaos Expansion method of random processes applied to the Navier-Stokes equations for a laminar flow. The method quantifies the extent, dependence and propagation of uncertainty through the model system and, in particular, a methodology for the calculation of the vortices trajectory variability,… More >

Seyed Mahmoud Hosseini¹, Farzad Shahabian²,Jan Sladek³, Vladimir Sladek³

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.1, pp. 39-66, 2011, DOI:10.3970/cmes.2011.071.039

Abstract The thermo-elastic wave propagation based on Green-Naghdi (GN) coupled thermo-elasticity (without energy dissipation) is studied in a functionally graded thick hollow cylinder considering uncertainty in constitutive mechanical properties under thermal shock loading. The meshless local Petrov-Galerkin method accompanied with Monte-Carlo simulation is developed to solve the stochastic boundary value problem. In the presented method, the mechanical properties of FGM are considered to be as random variables with Gaussian distribution and mean values equal to deterministic values reported in previous works, which are generated using Monte-Carlo simulation with various coefficients of variations (COVs). The time evolution for transient problems is treated… More >

C. R. A. Silva¹, H. P. Azikri de Deus¹, G.E. Mantovani², A.T. Beck³

CMES-Computer Modeling in Engineering & Sciences, Vol.67, No.2, pp. 119-150, 2010, DOI:10.3970/cmes.2010.067.119

Abstract In this paper, the Askey-Wiener scheme and the Galerkin method are used to obtain approximate solutions to stochastic beam bending on Winkler foundation. The study addresses Euler-Bernoulli beams with uncertainty in the bending stiffness modulus and in the stiffness of the foundation. Uncertainties are represented by parameterized stochastic processes. The random behavior of beam response is modeled using the Askey-Wiener scheme. One contribution of the paper is a sketch of proof of existence and uniqueness of the solution to problems involving fourth order operators applied to random fields. From the approximate Galerkin solution, expected value and variance of beam displacement… More >

C. Du¹, H. Bai², J. Qu³, X. Su^1,4

CMES-Computer Modeling in Engineering & Sciences, Vol.61, No.3, pp. 223-248, 2010, DOI:10.3970/cmes.2010.061.223

Abstract Second, or higher, order harmonics have great potential in fatigue life prediction. In this study, the dispersion properties of waves propagating in the nonlinear random media are investigated. An one dimensional nonlinear model based on the nonlinear Hikata stress-strain relation is used. We applied perturbation method, the Liouville transformation and the smoothing approximation method to solve the one dimensional nonlinear stochastic wave equation. We show easily that the dispersion equations for all higher order terms will be the same with the corresponding linear random medium by perturbation method. The linear stochastic equation with two random coefficients is greatly simplified to… More >

Bohou Xu¹, Yibing Yang¹, Zhong-Ping Jiang², Daniel W. Repperger³

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.2, pp. 159-174, 2010, DOI:10.3970/cmes.2010.057.159

Abstract A modified two-dimensional parameter-induced stochastic resonance (2D-PSR) system is proposed. Both theoretical and simulation results indicate that the 2D-PSR system performs a resonant-like behavior when system parameters are properly adjusted. When applied to degraded image processing, 2D-PSR technique is proved to be able to attain higher SNR gain than traditional linear filters. Due to its strong robustness to environmental changes, adaptability, and complementarities with other methods, the proposed 2D-PSR technique turns out to be promising in the field of image processing. More >