Xue-Qian Fang^1,2, Hong-Wei Liu¹, Yong-Mao Zhao¹, Guo-Quan Nie^1,1 and Jin-Xi Liu¹

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 145-164, 2014, DOI:10.3970/cmc.2014.040.145

Abstract Electro-elastic surface/interface around nano-sized piezoelectric inclusions shows great effect on the response of piezoelectric nano-structures. In this paper, a theoretical model is proposed to examine the surface/interface effect on the electromechanical responses around a nano-sized elliptical piezoelectric inclusion embedded in an infinite piezoelectric matrix under far-field loading with an arbitrary angle, and the effect of loading angle is considered Combining the conformal mapping technique and electro-elastic surface/interface theory, a closed form solution of this problem is obtained and the interactive effect between the surface/interface and the aspect ratio of the elliptical inclusion is examined. More >

Raveendranath U. Nair, Preethi D.S, R. M. Jha

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 131-144, 2014, DOI:10.3970/cmc.2014.040.131

Abstract Controllable artificial dielectrics are used in the design of radomes to enhance their electromagnetic (EM) performance. The fabrication of such radome wall structures with controllable dielectric parameters seems to be an arduous task. Further even minor fluctuations of dielectric properties of radome wall due to fabrication uncertainties tend to result in drastic degradation of radome performance parameters. In the present work, a novel inhomogeneous radome with graded variation of dielectric parameters is proposed which limits the constraints on fabrication and facilitates excellent EM performance characteristics. This radome wall consists of five dielectric layers cascaded such that the middle layer has… More >

J. Naqui¹, F. Martín¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 267-288, 2014, DOI:10.3970/cmc.2014.039.267

Abstract Metamaterial resonators are electrically small resonant particles useful for the implementation of effective media metamaterials. In this paper, some applications of metamaterial resonators (such as the split ring resonator -SRR-, the complementary split ring resonator -CSRR-, the folded stepped impedance resonator -SIR-, and the electric LC resonator), that exploit the symmetry properties of transmission lines loaded with such symmetric particles, are reviewed. This covers differential (balanced) lines with common mode suppression, linear and angular displacement sensors (including alignment sensors), angular velocity sensors, and radiofrequency barcodes. Advantages and drawbacks as compared to existing implementations are also discussed. More >

A.I. Dimitriadis¹, N.V. Kantartzis¹ and T.D. Tsiboukis¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 231-265, 2014, DOI:10.3970/cmc.2014.039.231

Abstract The most important surface susceptibility models for the electromagnetic characterization of periodic metafilms, based on the dipole approximation method, are systematically analyzed in this paper. Specifically, two well-known techniques, which lead to a set of local effective surface parameters, are investigated along with a new dynamic non-local modeling algorithm. The latter formulation is properly expanded, in order to be applicable for any arbitrary periodic metafilm, irrespective of its way of excitation. The featured schemes are then directly compared toward their ability to efficiently predict the reflection and transmission properties of several lossless and lossy metafilms. Their outcomes are carefully verified… More >

J.B. Niu¹, L.L. Li², Q. Xu¹, Z.H. Xia^1,3

CMC-Computers, Materials & Continua, Vol.38, No.1, pp. 31-41, 2013, DOI:10.3970/cmc.2013.038.031

Abstract Crack deflection and penetration at the interface of multi-wall carbon nanotube/amorphous carbon composites were studied via molecular dynamics simulations. In-situ strength of double-wall nanotubes bridging a matrix crack was calculated under various interfacial conditions. The structure of the nanotube reinforcement -ideal multi-wall vs. multi-wall with interwall sp³ bonding - influences the interfacial sliding and crack penetration. When the nanotube/matrix interface is strong, matrix crack penetrates the outermost layer of nanotubes but it deflects within the nanotubes with certain sp³ interwall bond density, resulting in inner wall pullout. With increasing the sp³ interwall bond density, the fracture mode becomes brittle; the… More >

L.B. Borkowski¹, K.C. Liu¹, A. Chattopadhyay¹

CMC-Computers, Materials & Continua, Vol.37, No.3, pp. 161-193, 2013, DOI:10.3970/cmc.2013.037.161

Abstract The microstructural variation in fiber-reinforced composites has a direct relationship with its local and global mechanical performance. When micromechanical modeling techniques for unidirectional composites assume a uniform and periodic arrangement of fibers, the bounds and validity of this assumption must be quantified. The goal of this research is to quantify the influence of microstructural randomness on effective homogeneous response and local inelastic behavior. The results indicate that microstructural progression from ordered to disordered decreases the tensile modulus by 5%, increases the shear modulus by 10%, and substantially increases the magnitude of local inelastic fields. The experimental and numerical analyses presented… More >

Raveendranath U Nair¹, R M Jha¹

CMC-Computers, Materials & Continua, Vol.37, No.2, pp. 109-121, 2013, DOI:10.3970/cmc.2013.037.109

Abstract Enhancement of electromagnetic performance of A-sandwich radome using aperture-type Jerusalem cross frequency selective surface (FSS) is presented. The Jerusalem cross FSS array is embedded in the mid-plane of the core of Asandwich radome to enhance the EM performance parameters over the entire Xband. For modeling the Jerusalem cross FSS embedded radome panel and evaluation of its EM performance parameters, equivalent transmission line method in conjunction with equivalent circuit model is used. A comparative study of Jerusalem cross FSS embedded A-sandwich radome and A-sandwich radome of identical material and thickness (core and skin layers) indicate that the new wall configuration has… More >

Chien-Ching Ma^1,2, Yi-Tzu Chen²

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 177-201, 2013, DOI:10.3970/cmc.2013.036.177

Abstract Functionally graded material (FGM) is a particulate composite with continuously changing its thermal and mechanical properties in order to raise the bonding strength in the discrete composite made from different phases of material constituents. Furthermore, FGM is a potent tool to create an intermediate layer in metal–ceramic composites to avoid the properties discontinuities and reduce, thereby, the residual stresses. For the nonhomogeneous problem, the mathematical derivation is much complicated than the homogeneous case since the material properties vary with coordinate. To analyze the problem, the Fourier transform is applied and the general solution in transform domain is obtained. The inverse… More >

Chyanbin Hwu¹, Tai-Liang Kuo²

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 135-153, 2013, DOI:10.3970/cmc.2013.036.135

Abstract The problems of the interface corners between two dissimilar anisotropic viscoelastic materials are studied in this paper. Through the use of the well-known correspondence principle between linear elasticity and linear viscoelasticity, fracture parameters in the Laplace domain can be obtained from the path-independent H-integral for the corresponding problems of anisotropic linear elastic materials. Further application of the correspondence relations for fracture parameters proposed in our recent study then leads us the solutions of fracture parameters in the time domain. To show the applicability and accuracy of the proposed method, several different kinds of numerical examples are presented such as a… More >

S.D. Akbarov^1,2, E. Hazar³, M. Eröz³

CMC-Computers, Materials & Continua, Vol.36, No.1, pp. 23-48, 2013, DOI:10.3970/cmc.2013.036.023

Abstract Within the scope of the piecewise homogeneous body model with utilizing of the three dimensional linearized theory of elastic waves in initially stressed bodies the influence of the shear-spring type imperfection of the contact conditions between the layers of the pre-stressed bi-layered plate strip resting on the rigid foundation, on the frequency response of this plate strip is investigated. The corresponding mathematical problem is solved numerically by employing FEM and numerical results illustrating the influence of the parameter characterizing the degree of the mentioned imperfectness, on the frequency response of the normal stress acting on the interface planes between the… More >