M. Negin¹, S. D. Akbarov^2,3, M. E. Erguven¹

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 25-62, 2014, DOI:10.3970/cmc.2014.042.025

Abstract Within the framework of the piecewise homogeneous body model the influence of the shear-spring type imperfect contact conditions on the dispersion relation of the generalized Rayleigh waves in the system consisting of the initially stressed covering layer and initially stressed half plane is investigated. The second version of the small initial deformation theory of the three-dimensional linearized theory of elastic waves in initially stressed bodies is applied and the elasticity relations of the materials of the constituents are described by the Murnaghan potential. The magnitude of the imperfectness of the contact conditions is estimated through… More >

S.D. Akbarov^1,2

CMC-Computers, Materials & Continua, Vol.33, No.1, pp. 63-85, 2013, DOI:10.3970/cmc.2013.033.063

Abstract An attempt is made into the investigation of longitudinal axisymmetric wave propagation in the DWCNT with the use of the exact equations of motion of the linear theory of elastodynamics. The DWCNT is modeled as concentricallynested two circular hollow cylinders between which there is free space. The difference in the radial displacements of these cylinders is coupled with the van der Waals forces and it is assumed that full slipping conditions occur on the inner surface of the outer tube and on the outer surface of the inner tube. Numerical results on the influence of More >

S. D. Akbarov^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.4, pp. 387-421, 2013, DOI:10.3970/cmes.2013.092.387

Abstract Flexural wave dispersion in finitely pre-stretched (or pre-compressed) solid and hollow, circular cylinders is investigated with the use of the threedimensional linearized theory of elastic waves in initially stressed bodies. It is assumed that the initial strains in the cylinders are homogeneous and correspond to the uniaxial tension, or compression, along their central axes. The elasticity relations of the cylinders’ materials are described by the harmonic potential. The analytical solution of the corresponding field equations is presented and, using these solutions, the dispersion equations for the cases under consideration are obtained. The dispersion equations are… More >

Ridha Djebali¹, Mohsen Toujani², Bernard Pateyron³

CMC-Computers, Materials & Continua, Vol.37, No.3, pp. 147-160, 2013, DOI:10.3970/cmc.2013.037.147

Abstract In this paper a study of the atmospheric plasma spraying process was conducted. The Jets&Poudres code was used to solve the partial differential equations for the conservation of mass, momentum and energy involved in the problem together with the K-e turbulent model. The Taguchi technique was used to study the influence of processing factors on droplet impact properties obtained on dense zirconia (ZrO₂) under H₂Ar75% plasma gas that allow optimal functioning condition. The test of the operating parameters for the studied ranges showed that the "thermal power" factor plays a key role on the state of sprayed More >

Galussi AA^1,2, ME Moya^1,2, LR Zimmermann¹, FG Marchese^1,2, YG Gillij^1,2, F Torres^1,2

Phyton-International Journal of Experimental Botany, Vol.81, pp. 255-260, 2012, DOI:10.32604/phyton.2012.81.255

Abstract Mnesithea selloana (known as cola de largarto, teyú ruguay) is a spring-summer-fall species that flowers and fructifies in that period; it has good forage quality, and it is in danger of extinction in the natural grasslands at the study region. The objectives of this work were to study the sinflorescence morphology, and the maturity and quality of the caryopsis to know its reproductive aspects in relation to the dissemination of this especies in grazing areas. The sinflorescence was studied in two plants during a period of 45 days, between October and December 2010, within an experimental… More >

S.D. Akbarov^1,2

CMC-Computers, Materials & Continua, Vol.32, No.1, pp. 29-60, 2012, DOI:10.3970/cmc.2012.032.029

Abstract By the use of the Murnaghan potential the influence of third order elastic constants on axisymmetric longitudinal wave propagation velocity in a pre-stressed two-layered circular hollow cylinder is investigated. This investigation is carried out within the scope of the piecewise homogeneous body model by utilizing the first version of the small initial deformation theory of the Three-dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies. Numerical results are obtained and analyzed for the cases where the material of the outer hollow cylinder material is aluminum, but the material of the inner cylinder is steel More >

H.H. Luo¹, Z.H. Tan^1,2, X. Han¹, C. Chen¹

CMC-Computers, Materials & Continua, Vol.32, No.1, pp. 1-14, 2012, DOI:10.3970/cmc.2012.032.001

Abstract The dynamic properties of aluminium alloy foam were investigated by using split Hopkinson pressure bar (SHPB) with diameter of 40 mm. The aluminium alloy pressure bar and pulse shape technique were used to modify the traditional SHPB due to the low impedance of aluminium alloy foam. Wave dispersion correction on the aluminium alloy pressure bar was studied by Fourier series. And the finite element numerical simulation was also performed to demonstrate and validate the dispersion correction results by Fourier series method. The reflected and transmitted wave measured in SHPB experiments were corrected by the backward More >

S. D. Akbarov^1,2, C. Ipek³

CMC-Computers, Materials & Continua, Vol.30, No.2, pp. 99-144, 2012, DOI:10.3970/cmc.2012.030.099

Abstract This paper studies the dispersion of the axisymmetric longitudinal wave propagation in the pre-strained hollow cylinder consisting of two-layers under the shear-spring type imperfectness of the contact conditions between these layers. The investigations are made within the framework of the piecewise homogeneous body model by utilizing the 3D linearized theory of elastic waves in elastic bodies with initial stresses. It is assumed that the layers of the cylinder are made from compressible hyper-elastic materials and their elasticity relations are given through the harmonic potential. The degree of the mentioned imperfectness is estimated by the shear-spring More >

Surkay D. Akbarov^1,2, Tamer Kepceler¹, M. Mert Egilmez¹

CMC-Computers, Materials & Continua, Vol.30, No.1, pp. 83-98, 2012, DOI:10.3970/cmc.2012.030.083

Abstract This paper develops the investigations started in a work by Akbarov, Kepceler and Mert Egilmez (2011) and studies the some particularities of the torsional wave dispersion in a finitely pre-deformed sandwich hollow cylinder. The mentioned particularities relate to the influence of the stiffness ratio of the core and face layers' materials and the influence of the thickness ratio of these layers on the dispersion character of the wave under consideration. Moreover, the mentioned influences are studied for the various values of the parameter which characterizes the initial strains in the cylinder's layers. The mechanical relations More >

Chih-Wen Chang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.2, pp. 65-92, 2012, DOI:10.3970/cmes.2012.088.065

Abstract We utilize a regularized integral equation scheme to resolve the three-dimensional backward advection-dispersion equation (BADE) for identifying the groundwater pollution source identification problems in this research. First, the Fourier series expansion method is employed to estimate the concentration field C(x, y, z, t) at any time t < T. Second, we contemplate a direct regularization by adding an extra term a(x, y, z, 0) to transform a second-kind Fredholm integral equation for C(x, y, z, 0). The termwise separable property of the kernel function permits us to acquire a closed-form regularized solution. In addition, a More >