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 >

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 >

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 >

V. G. Yakhno¹, B. Çiçek²

CMC-Computers, Materials & Continua, Vol.44, No.3, pp. 141-166, 2014, DOI:10.3970/cmc.2014.044.141

Abstract A method for an approximate computation of the electric and magnetic Green’s functions for the time-harmonic Maxwell’s equations in the general electrically gyrotropic materials is proposed. This method is based on the Fourier transform meta-approach: the equations for electric and magnetic fields are written in terms of images of the Fourier transform with respect to space variables and as a result of it the linear algebraic systems for finding Fourier images of the columns of the Green’s functions are obtained. The explicit formulas for the solutions of the obtained systems have been found. Finally, elements of the Green’s functions are… More >