Wenzhi Xu¹, ZhuoJia Fu^1,*, Qiang Xi¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.010437

Abstract Acoustic wave propagation through an inhomogeneous medium may lead to undergo substantial modification. This paper proposed a Green’s functions-based method for the simulation of wave propagation through inhomogeneous medium waveguides. Under ideal conditions, a modified wave equation is derived by variable transformations, in which only the wave speed varies with spatial coordinates. Based on the modified wave equation the acoustic Green’s functions are derived. Then, the localized method of fundamental solution (LMFS) in conjunction with the acoustic Green’s functions is introduced to solve the modified wave equation. In the LMFS, the acoustic Green’s function is considered as its basic function… More >

Linjuan Wang^1,*, Jianxiang Wang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09355

Abstract The prediction of overall dynamics of composite materials has been an intriguing research topic more than a century, and numerous approaches have been developed for this topic. One of the most successful representatives is the classical micromechanical models which assume that the behavior of a composite is the same as its constituents except for the difference in mechanical properties, e.g., effective moduli. With the development of advanced composite materials in recent years, especially metamaterials, it is found that the classical micromechanical models cannot describe complex dynamic responses of composites such as the dispersion and bandgaps of elastic waves. Thus, some… More >

A. Arulmary^1,*, V. Rajamani², T. Kavitha²

Computer Systems Science and Engineering, Vol.46, No.2, pp. 1617-1630, 2023, DOI:10.32604/csse.2023.034681

Abstract The method opted for accuracy, and no existing studies are based on this method. A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube (SWCNT) Field Effect Transistor as a photodetector is carried out. In the proposed device, better performance is achieved by increasing the diameter and introducing a new single halo (SH) doping in the channel length of the CNTFET device. This paper is a study and analysis of the performance of a Carbon Nano Tube Field Effect Transistor (CNTFET) as a photodetector using the self-consistent Poisson and Green function method. The… More >

Xiangli Liu¹, S. I. Golubov¹, C. H. Woo^1,2, Hanchen Huang³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.6, pp. 527-540, 2004, DOI:10.3970/cmes.2004.005.527

Abstract A Green’s function technique is developed for the relaxation of simulation cell boundaries in the modelling of dislocation interactions using molecular dynamics. This method allows the replacement of fixed or periodical boundary conditions with flexible boundary conditions, thus minimizing the artificial effects due to images forces introduced by the fixed boundary condition, or the periodic repetition of simulation cells. The effectiveness of the Green’s function in the removal of the fixed boundary image forces is first checked in the atomistic simulation involving the glide of the a/2<110> dislocation in bcc tungsten. This method is then applied to study the reaction… More >

Weiming Lee

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 178-178, 2019, DOI:10.32604/icces.2019.05190

Abstract This paper presents a semi-analytical approach to solve anti-plane dynamic Green’s functions for an elastic infinitely extended isotropic solid (matrix) containing multiple elliptical inclusions with imperfect interfaces. The multipole expansions of anti-plane displacement for the matrix and inclusion are formulated in terms of angular and radial Mathieu functions to solve the dynamic Green’s functions. Instead of using the complex addition theorem, frequently used in the traditional multipole method for a multiply-connected domain problem, the multipole expansion is directly computed in each local elliptical coordinate system. A linear spring model with vanishing thickness is employed to character the imperfect interface. The… More >

Cristiano Ubessi¹, Federico C. Buroni^2,*, Gabriel Hattori³, Andrés Sáez⁴, Rogério J. Marczak¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.1, pp. 104-104, 2019, DOI:10.32604/icces.2019.05420

Abstract Efficient three-dimensional infinite Green’s function and its first- and second-order derivatives for materials with piezoelectric coupling are studied in this paper. The procedure is based on an explicit solution recently introduced by the authors which presents three valuable characteristics: (i) it is explicit in terms of the Stroh’s eigenvalues, (ii) it remains well-defined when some Stroh’s eigenvalues are repeated (mathematical degeneracy) or nearly equal (quasi-mathematical degeneracy), and (iii) it is exact. Then, this solution is used to compute coefficients for a double Fourier series representation of the Green’s function and its derivatives. These Fourier expansion representations are realvariable which is… More >

Edmund Chadwick¹, Apostolis Kapoulas

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.4, pp. 331-343, 2014, DOI:10.3970/cmes.2014.102.331

Abstract Boundary element models in inviscid (Euler) flow dynamics for a manoeuvring body are difficult to formulate even for the steady case; Although the potential satisfies the Laplace equation, it has a jump discontinuity in twodimensional flow relating to the point vortex solution (from the 2π jump in the polar angle), and a singular discontinuity region in three-dimensional flow relating to the trailing vortex wake. So, instead models are usually constructed bottom up from distributions of these fundamental solutions giving point vortex thin body methods in two-dimensional flow, and panel methods and vortex lattice methods in three-dimensional flow amongst others. Instead,… More >

E.F. Fontes Jr¹, J.A.F. Santiago¹, J.C.F. Telles¹

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.3, pp. 211-228, 2014, DOI:10.3970/cmes.2014.102.211

Abstract An iterative coupling procedure using different meshless methods is presented to solve linear elastic fracture mechanic (LEFM) problems. The domain of the problem is decomposed into two sub-domains, where each one is addressed using an appropriate meshless method. The method of fundamental solutions (MFS) based on the numerical Green’s function (NGF) procedure to generate the fundamental solution has been chosen for modeling embedded cracks in the elastic medium and the meshless local Petrov-Galerkin (MLPG) method has been chosen for modeling the remaining sub-domain. Each meshless method runs independently, coupled with an iterative update of interface variables to achieve the final… More >

Y.C. Shiah¹, C.L. Tan², Y.H. Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.4, pp. 243-257, 2013, DOI:10.3970/cmes.2013.096.243

Abstract The present authors have recently proposed an efficient, alternative approach to numerically evaluate the fundamental solution and its derivatives for 3D general anisotropic elasticity. It is based on a double Fourier series representation of the exact, explicit form of the Green’s function derived by Ting and Lee (1997). This paper reports on the successful implementation of the fundamental solution and its derivatives based on this Fourier series scheme in the boundary element method (BEM) for 3D general anisotropic elastostatics. Some numerical examples of stress concentration problems and a crack problem are presented to demonstrate the veracity of the implementation. The… More >

Y. C. Shiah¹, C. L. Tan², V.G. Lee³

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.3, pp. 205-226, 2008, DOI:10.3970/cmes.2008.034.205

Abstract The main impediment to the development of efficient algorithms for the stress analysis of 3D generally anisotropic elastic solids using the boundary element method (BEM) and the local boundary integral equation (LBIE) meshless method over the years is the complexity of the fundamental solutions and the computational burden to evaluate them. The ability to analytically simplify and reduce them into as explicit a form as possible so that they can be directly computed will offer significant cost savings. In addition, they facilitate easy implementation using existing numerical algorithms with the above-mentioned methods that have been developed for isotropy. In this… More >