Yongsong Li¹, Xiaomeng Yin², Yanming Xu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.2, pp. 471-488, 2022, DOI:10.32604/cmes.2022.020201

Abstract The isogeometric boundary element technique (IGABEM) is presented in this study for steady-state inhomogeneous heat conduction analysis. The physical unknowns in the boundary integral formulations of the governing equations are discretized using non-uniform rational B-spline (NURBS) basis functions, which are utilized to build the geometry of the structures. To speed up the assessment of NURBS basis functions, the B´ezier extraction approach is used. To solve the extra domain integrals, we use a radial integration approach. The numerical examples show the potential of IGABEM for dimension reduction and smooth integration of CAD and numerical analysis. More >

F. S. Bayones¹, A. M. Abd-Alla², A. M. Farhan^3,4,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 3339-3352, 2021, DOI:10.32604/cmc.2021.016021

Abstract The present article deals with the investigation thermal stress of a magnetothermoelastic cylinder subjected to rotation, open or closed circuit, thermal and mechanical boundary conditions. The outer and inner surfaces of the cylinder are subjected to both mechanical and thermal boundary conditions. A The transient coupled thermoelasticity in an infinite cylinder with its base abruptly exposed to a heat flux of a decaying exponential function of time is devised solve by the finite-difference method. The fundamental equations’ system is solved by utilizing an implicit finite-difference method. This current method is a second-order accurate in time and space; it is also… More >

Surkay D. Akbarov^1,2,*, Emin T. Bagirov²

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 315-348, 2019, DOI:10.32604/cmes.2019.07732

Abstract The paper deals with the study of the influence of the non-homogeneous pre-stresses in the system consisting of the hollow cylinder and surrounding elastic medium on the frequency response of this system caused by the time-harmonic ring load acting in the interior of the cylinder. The axisymmetric problem is considered and it is assumed that in the initial state, the system is compressed in the radial direction with homogeneously distributed static forces as a result of which, non-homogeneous pre-stresses (or initial stresses) appear in that. It is also assumed that after these pre-stresses appear in the interior of the cylinder,… More >

Hiroshi Okada^*, Tatsuro Ishizaka, Akira Takahashi, Koichiro Arai, Yasunori Yusa

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 10-11, 2019, DOI:10.32604/icces.2019.05037

Abstract In this paper, a new three-dimensional J-integral for non-homogeneous solids undergoing large deformation and associated with residual stresses is presented. The formulation of J-integral involves the strain energy density W that is generally defined by the integral W = ∫₀^t τ_ijε^·_ijdt⁻ over the entire deformation history of a material point where t_ij and ε^·_ij are the components of the Kirchhoff stress and those of velocity strain. t and t represents the time. It is assumed that at t = 0 the body is free from any deformation and therefore the stresses are zeros.
Residual stresses are… More >

V. Sladek¹, J. Sladek¹, M. Tanaka²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.1, pp. 69-84, 2005, DOI:10.3970/cmes.2005.007.069

Abstract An efficient numerical method is proposed for 2-d potential problems in anisotropic media with continuously variable material coefficients. The method is based on the local integral equations (utilizing a fundamental solution) and meshfree approximation of field variable. A lot of numerical experiments are carried out in order to study the numerical stability, accuracy, convergence and efficiency of several approaches utilizing various interpolations. More >

Liu Liqi¹, Wang Haitao^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.109-110, No.4, pp. 303-324, 2015, DOI:10.3970/cmes.2015.109.303

Abstract This paper presents a three-dimensional (3-D) boundary element method (BEM) scheme based on the Radial Integration Method (RIM) for wave propagation analysis of continuously non-homogeneous problems. The Kelvin fundamental solutions are adopted to derive the boundary-domain integral equation (BDIE). The RIM proposed by Gao (Engineering Analysis with Boundary Elements 2002; 26(10):905-916) is implemented to treat the domain integrals in the BDIE so that only boundary discretization is required. After boundary discretization, a set of second-order ordinary differential equations with respect to time variable are derived, which are solved using the Wilson-q method. Main advantages of the proposed method are that… More >

A. Tadeu¹, P. Stanak², J. Antonio¹, J. Sladek², V. Sladek²

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.5, pp. 345-378, 2015, DOI:10.3970/cmes.2015.107.345

Abstract This paper implements a numerical method based on the mutual coupling of the boundary element method (BEM) and the meshless local Petrov-Galerkin (MLPG) method to simulate elastic wave propagation in fluid-filled boreholes. The fluid-solid interaction is solved in the frequency domain assuming longitudinally invariant geometry in the axial direction (2.5D formulation).
This model is used to assess the influence of the non-homogeneous material properties of a borehole wall that can be caused by a damaged zone, construction process or the ageing of material. The BEM is used to model propagation within the unbounded homogeneous domain and the fluid domain… More >

A. Tadeu¹, P. Stanak², J. Sladek², V. Sladek², J. Prata¹, N. Simões¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.6, pp. 489-516, 2013, DOI:10.3970/cmes.2013.093.489

Abstract This paper presents a technique that couples the boundary element method (BEM) with the meshless local Petrov-Galerkin (MLPG) method, formulated in the frequency domain. It is then used to study the transient heat diffusion through a two-dimensional unbounded medium containing confined subdomains where the material properties vary from point to point. To exploit the advantages of each method, the BEM is used for the homogeneous unbounded domain and the MLPG method is used for the non-homogeneous confined subdomains. The nodal points placed at the interface between the confined subdomains and the unbounded homogenous medium are used to couple the BEM… More >

S.Yu. Reutskiy¹

CMES-Computer Modeling in Engineering & Sciences, Vol.51, No.2, pp. 115-142, 2009, DOI:10.3970/cmes.2009.051.115

Abstract In this paper a new numerical technique for problems of free vibrations of arbitrary shaped non-homogeneous membranes:∇²w + k²q(x)w = 0, x∈ Ω⊂R², B[w] = 0, x∈∂Ω is presented. Homogeneous membranes of a complex form are considered as a particular case. The method is based on mathematically modeling of physical response of a system to excitation over a range of frequencies. The response amplitudes are then used to determine the resonant frequencies. Applying the method, one gets a sequence of boundary value problems (BVPs) depending on the spectral parameter k. The eigenvalues are sought as positions of the maxima of… More >

Sarang Seyrafian¹, Behrouz Gatmiri², Asadollah Noorzad³

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.2, pp. 115-126, 2006, DOI:10.3970/cmes.2006.015.115

Abstract An analytical solution is presented for the response of a non-homogeneous saturated poroelastic half-space under the action of a time-harmonic vertical point load on its surface. The shear modulus is assumed to increase continuously with depth and also the media is considered to obey Biot's poroelastic theory. The system of governing partial differential equations, based on the mentioned assumptions, is converted to ordinary differential equations' system by means of Hankel integral transforms. Then the system of equations is solved by use of generalized power series(Frobenius method) and the expressions for displacements in the interior of the media or in the… More >