Y. Miao¹, T.G. HE¹, H. Luo^1,2, H.P. Zhu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.6, pp. 481-498, 2012, DOI:10.3970/cmes.2012.085.481

Abstract Combined the hybrid boundary node method (Hybrid BNM) and the dual reciprocity principle, a truly boundary-type meshless method, namely, dual hybrid boundary node method (Dual Hybrid BNM) is presented for solving transient dynamic fracture problems. The enriched basis functions in moving least squares (MLS) approximation is presented for simulating the singularity of the stress field on the tip of the fracture. The solution in Dual Hybrid BNM is divided into particular solution and complementary solution. The complementary solution is solved by means of Hybrid BNM, and the particular solution is approximated by using radial basis functions (RBF). The inner nodes… More >

Jiaoyan Li¹, Xianqiao Wang², James D. Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.5, pp. 463-480, 2012, DOI:10.3970/cmes.2012.085.463

Abstract This paper presents a novel multiple time scale algorithm integrated with the concurrent atomic/atom-based continuum modeling, which involves molecular dynamic (MD) simulation and coarse-grained molecular dynamic (CG-MD) simulation. To capture the key features of the solution region while still considering the computational efficiency, we decompose it into two sub-regions in space and utilize the central difference method with different time steps for different sub-regions to march on in time. Usually, the solution region contains a critical field and a non-critical far field. For the critical field (named atomic region) modeled by MD simulation, a relatively small time step is used… More >

Wei-Chung Tien¹, Yue-Tzu Yang¹, Cha’o-Kuang Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.5, pp. 447-462, 2012, DOI:10.3970/cmes.2012.085.447

Abstract Both buoyancy effects of thermal and mass diffusion in the natural convection flow about a vertical plate are considered in this paper. The non-linear coupled differential governing equations for velocity, temperature and concentration fields are solved by using the homotopy analysis method. Without the need of iteration, the obtained solution is in the form of an infinite power series which indicates those series have high accuracy when comparing it with other-generated by the traditional method. The impact of the Prandtl number, Schmidt number and the buoyancy parameter on the flow are widely discussed in detail. More >

V.A. Buryachenko^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.5, pp. 417-446, 2012, DOI:10.3970/cmes.2012.085.417

Abstract We consider a linearly elastic composite medium, which consists of a homogeneous matrix containing a statistically homogeneous set of multimodal spherical inclusions modeling the morphology of heterogeneous solid propellants (HSP). Estimates of effective elastic moduli are performed using the multiparticle effective field method (MEFM) directly taking into account the interaction of different inclusions. Because of this, the effective elastic moduli of the HSP evaluated by the MEFM are sensitive to both the relative size of the inclusions (i.e., their multimodal nature) and the radial distribution functions (RDFs) estimated from experimental data, as well as from the ensembles generated by the… More >

V.A. Buryachenko^1,2, T.L. Jackson^2,3, G. Amadio³

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.5, pp. 379-416, 2012, DOI:10.3970/cmes.2012.085.379

Abstract We consider a composite medium, which consists of a homogeneous matrix containing a statistically homogeneous set of multimodal spherical inclusions. This model is used to represent the morphology of heterogeneous solid propellants (HSP) that are widely used in the rocket industry. The Lubachevsky-Stillinger algorithm is used to generate morphological models of HSP with large polydisperse packs of spherical inclusions. We modify the algorithm by proposing a random shaking procedure that leads to the stabilization of a statistical distribution of the simulated structure that is homogeneous, highly mixed, and protocol independent (in sense that the statistical parameters estimated do not depend… More >

N.A. Gasilov¹, I.F. Hashimoglu², S.E. Amrahov³, A.G. Fatullayev¹

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.4, pp. 367-378, 2012, DOI:10.3970/cmes.2012.085.367

Abstract In this paper, we consider a high-order linear differential equation with fuzzy forcing function and with fuzzy initial values. We assume the forcing function be in a special form, which we call triangular fuzzy function. We present solution as a fuzzy set of real functions such that each real function satisfies the initial value problem by some membership degree. We propose a method to find the fuzzy solution. We present an example to illustrate applicability of the proposed method. More >

Ju’e Yang¹, Hongying Huang², Dehao Yu³

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.4, pp. 347-366, 2012, DOI:10.3970/cmes.2012.085.347

Abstract In this paper, a new domain decomposition method is suggested for the stationary Stokes equations on unbounded domain and its convergence is proved. We draw an artificial boundary to make the domain into two parts: one is bounded, in which we use the mixed finite element method; the other is unbounded, in which we apply the natural boundary reduction. Then we change the sub-problem on the unbounded domain onto a one in a bounded domain and we use the Dirichlet to Neumann(DtN) alternating algorithm to solve the resulting mixed system. The theoretical results as well as the numerical examples show… More >

M. Amdi¹, M. Souli¹, J. Hargreaves², F. Erchiqui³

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.4, pp. 329-346, 2012, DOI:10.3970/cmes.2012.085.329

Abstract Simulation of vibroacoustic problems becomes more and more the focus of engineering in the last decades for acoustic comfort in automotive industry to reduce noise and vibration inside a cabin and also in sport industry to analyze sound produced by a club impacting a golf ball to avoid unexpected noise problems during the design process. Traditionally, Finite element and Boundary element methods are used in frequency domain to model pressure noise from structure vibration in low and mid frequency range. These methods require velocity in frequency domain on the vibrating structure as boundary conditions. To analyze pressure noise from impact… More >

Zhen Luo¹, Nong Zhang¹, Tao Wu^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.4, pp. 299-328, 2012, DOI:10.3970/cmes.2012.085.299

Abstract This paper presents a meshless Galerkin level-set method (MGLSM) for shape and topology optimization of compliant mechanisms of geometrically nonlinear structures. The design boundary of the mechanism is implicitly described as the zero level set of a Lipschitz continuous level set function of higher dimension. The moving least square (MLS) approximation is used to construct the meshless shape functions with the global Galerkin weak-form in terms of a set of arbitrarily distributed nodes. The MLS shape function is first employed to parameterize the level set function via the surface fitting rather than interpolation, and then used to implement the meshless… More >

A.P.S. Selvadurai^1,2, H. Nikopour²

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.3, pp. 279-298, 2012, DOI:10.3970/cmes.2012.085.279

Abstract This paper examines the influence of a through crack on the overall flexural behaviour of a layered composite Carbon Fibre Reinforced Polymer (CFRP) plate that is fixed boundary along a circular boundary. Plates with different through crack configurations and subjected to uniform air pressure loading are examined both experimentally and computationally. In particular, the effect of crack length and its orientation on the overall pressure-deflection behaviour of the composite plate is investigated. The layered composite CFRP plate used in the experimental investigation consisted of 11 layers of a polyester matrix unidirectionally reinforced with carbon fibres. The bulk fibre volume fraction… More >