Ivano Benedetti^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 4-6, 2021, DOI:10.32604/icces.2021.08213

Abstract A recently developed novel three-dimensional (3D) computational framework for the analysis of polycrystalline materials at the grain scale is described in this lecture. The framework is based on the employment of: i) 3D Laguerre-Voronoi tessellations for the representation of the micro-morphology of polycrystalline materials; ii) boundary integral equations for the representation of the mechanics of the individual grains; iii) suitable cohesive traction-separation laws for the representation of the multi-physics behavior of the interfaces (either inter-granular or trans-granular) within the aggregate, which are the seat of damage initiation and evolution processes, up to complete decohesion and failure. The lecture will describe… More >

Mohamed Abdelsabour Fahmy^1,2,*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 59-76, 2021, DOI:10.32604/cmc.2021.015115

Abstract The main purpose of the current article is to develop a novel boundary element model for solving fractional-order nonlinear generalized porothermoelastic wave propagation problems in the context of temperature-dependent functionally graded anisotropic (FGA) structures. The system of governing equations of the considered problem is extremely very difficult or impossible to solve analytically due to nonlinearity, fractional order diffusion and strongly anisotropic mechanical and physical properties of considered porous structures. Therefore, an efficient boundary element method (BEM) has been proposed to overcome this difficulty, where, the nonlinear terms were treated using the Kirchhoff transformation and the domain integrals were treated using… More >

Weidong Lei¹, Hai Zhou^1,*, Hongjun Li², Rui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 577-597, 2021, DOI:10.32604/cmes.2021.011857

Abstract In order to simulate the propagation process of subway vibration of parallel tunnels in semi-infinite rocks or soils, time domain boundary element method (TD-BEM) formulation for analyzing the dynamic response of twin-parallel circular tunnels in an elastic semi-infinite medium is developed in this paper. The time domain boundary integral equations of displacement and stress for the elastodynamic problem are presented based on Betti’s reciprocal work theorem, ignoring contributions from initial conditions and body forces. In the process of establishing time domain boundary integral equations, some virtual boundaries are constructed between finite boundaries and the free boundary to form a boundary… More >

Leilei Chen¹, Kunpeng Li¹, Xuan Peng², Haojie Lian^3,4,*, Xiao Lin⁵, Zhuojia Fu⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 125-146, 2021, DOI:10.32604/cmes.2021.012821

Abstract This paper presents an isogeometric boundary element method (IGABEM) for transient heat conduction analysis. The Non-Uniform Rational B-spline (NURBS) basis functions, which are used to construct the geometry of the structures, are employed to discretize the physical unknowns in the boundary integral formulations of the governing equations. B´ezier extraction technique is employed to accelerate the evaluation of NURBS basis functions. We adopt a radial integration method to address the additional domain integrals. The numerical examples demonstrate the advantage of IGABEM in dimension reduction and the seamless connection between CAD and numerical analysis. More >

Mohamed Abdelsabour Fahmy^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 175-199, 2021, DOI:10.32604/cmes.2021.012218

Abstract The main aim of this paper is to propose a new memory dependent derivative (MDD) theory which called threetemperature nonlinear generalized anisotropic micropolar-thermoelasticity. The system of governing equations of the problems associated with the proposed theory is extremely difficult or impossible to solve analytically due to nonlinearity, MDD diffusion, multi-variable nature, multi-stage processing and anisotropic properties of the considered material. Therefore, we propose a novel boundary element method (BEM) formulation for modeling and simulation of such system. The computational performance of the proposed technique has been investigated. The numerical results illustrate the effects of time delays and kernel functions on… More >

Hongyin Yang^1,2, Jiwei Zhong^1,*, Ying Wang³, Xingquan Chen², Xiaoya Bian²

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 807-824, 2020, DOI:10.32604/cmes.2020.010936

Abstract In this paper, general interpolating isogeometric boundary node method (IIBNM) and isogeometric boundary element method (IBEM) based on parameter space are proposed for 2D elasticity problems. In both methods, the integral cells and elements are defined in parameter space, which can reproduce the geometry exactly at all the stages. In IIBNM, the improved interpolating moving leastsquare method (IIMLS) is applied for field approximation and the shape functions have the delta function property. The Lagrangian basis functions are used for field approximation in IBEM. Thus, the boundary conditions can be imposed directly in both methods. The shape functions are defined in… More >

Shige Wang¹, Zhongwang Wang¹, Leilei Chen¹, Haojie Lian^2,3,*, Xuan Peng⁴, Haibo Chen⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 585-604, 2020, DOI:10.32604/cmes.2020.09904

Abstract The paper applied the isogeometric boundary element method (IGABEM) to thermoelastic problems. The Non-Uniform Rational B-splines (NURBS) used to construct geometric models are employed to discretize the boundary integral formulation of the governing equation. Due to the existence of thermal stress, the domain integral term appears in the boundary integral equation. We resolve this problem by incorporating radial integration method into IGABEM which converts the domain integral to the boundary integral. In this way, IGABEM can maintain its advantages in dimensionality reduction and more importantly, seamless integration of CAD and numerical analysis based on boundary representation. The algorithm is verified… More >

Yui-Chuin Shiah^{1, *}, Sheng-Chi Huang¹, M. R. Hematiyan²

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 701-727, 2020, DOI:10.32604/cmc.2020.010417

Abstract In engineering practice, analysis of interfacial thermal stresses in composites is a crucial task for assuring structural integrity when sever environmental temperature changes under operations. In this article, the directly transformed boundary integrals presented previously for treating generally anisotropic thermoelasticity in two-dimension are fully regularized by a semi-analytical approach for modeling thin multi-layers of anisotropic/isotropic composites, subjected to general thermal loads with boundary conditions prescribed. In this process, an additional difficulty, not reported in the literature, arises due to rapid fluctuation of an integrand in the directly transformed boundary integral equation. In conventional analysis, thin adhesives are usually neglected due… More >

Weihua Fang¹, Zhilin An², Tiantang Yu^{2, *}, Tinh Quoc Bui^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 929-962, 2020, DOI:10.32604/cmc.2020.05022

Abstract Numerical analysis of unsteady heat transfer problems with complex geometries by the isogeometric boundary element method (IGABEM) is presented. The IGABEM possesses many desirable merits and features, for instance, (a) exactly represented arbitrarily complex geometries, and higher-order continuity due to nonuniform rational B-splines (NURBS) shape functions; (b) using NURBS for both field approximation and geometric description; (c) directly utilizing geometry data from computer-aided design (CAD); and (d) only boundary discretization. The formulation of IGABEM for unsteady heat transfer is derived. The domain discretization in terms of IGABEM for unsteady heat transfer is required as that in traditional BEM. The internal… More >

A.P.Cisilino¹, M.H. Aliabadi²

Structural Durability & Health Monitoring, Vol.6, No.3&4, pp. 213-238, 2010, DOI:10.3970/sdhm.2010.006.213

Abstract This paper presents a review of the dual boundary element method for modeling crack growth in two-dimensional and three-dimensional mixed mode problems. The modeling strategy for crack coalescence using the DBEM is presented and comparisons are made with alternative solutions where available. Also presented are three-dimensional multiple crack growth and microcrack growth problems. More >