E. Hayward¹, C. Deo¹

CMC-Computers, Materials & Continua, Vol.16, No.2, pp. 101-116, 2010, DOI:10.3970/cmc.2010.016.101

Abstract Damage cascades representative of those that would be induced by neutron irradiation have been simulated in systems of pure iron and iron containing 0.01 at.% hydrogen. Results from molecular dynamics simulations using three different embedded-atom method (EAM) type potentials are compared for primary knock-on atom energies of 5, 10, and 20 keV to assess the effect of hydrogen on the primary damage state. We examine the influence of hydrogen on the primary damage state due to a single radiation cascade. These results can serve as an atomistic database for methods and simulations for long time scale evolution of radiation damage. More >

C.M. Hefferan¹, S.F. Li¹, J. Lind¹, U. Lienert², A.D. Rollett³, P. Wynblatt³, R.M. Suter^1,3

CMC-Computers, Materials & Continua, Vol.14, No.3, pp. 209-220, 2009, DOI:10.3970/cmc.2009.014.209

Abstract We have measured and reconstructed via forward modeling a small volume of microstructure of high purity, well annealed nickel using high energy x-ray diffraction microscopy (HEDM). Statistical distributions characterizing grain orientations, intra-granular misorientations, and nearest neighbor grain misorientations are extracted. Results are consistent with recent electron backscatter diffraction measurements. Peaks in the grain neighbor misorientation angle distribution at 60 degrees (∑3) and 39 degrees (∑9) have resolution limited widths of ≈ 0.14 degree FWHM. The analysis demonstrates that HEDM can recover grain and grain boundary statistics comparable to OIM volume measurements; more extensive data sets will lead to full, five… More >

Stephen R. Niezgoda¹, Surya R. Kalidindi^1,2

CMC-Computers, Materials & Continua, Vol.14, No.2, pp. 79-98, 2009, DOI:10.3970/cmc.2009.014.079

Abstract The generalized Hough transform is a common technique for feature detection in image processing. In this paper, we develop a size invariant Hough framework for the detection of arbitrary shapes in three dimensional digital microstructure datasets. The Hough transform is efficiently implemented via kernel convolution with complex Hough filters, where shape is captured in the magnitude of the filter and scale in the complex phase. In this paper, we further generalize the concept of a Hough filter by encoding other parameters of interest (e.g. orientation of plate or fiber constituents) in the complex phase, broadening the applicability of Hough transform… More >

Hao-Miao Zhou¹, Fang Li¹, Qiang Ye¹, Ji-Xiang Zhao¹, Zhe-Lei Xia¹, YingTang², Jing Wei³

CMC-Computers, Materials & Continua, Vol.13, No.3, pp. 235-248, 2009, DOI:10.3970/cmc.2009.013.235

Abstract At present, there are many methods about Young's modulus measurement of thin films, but so far there is no recognized simple, non-destructive and cheaper standard measurement method. Considering thin films with various thicknesses were sputter deposited on the magnetostrictive resonator and monitoring the resonator's first-order longitudinal resonant frequency shift both before and after deposition induced by external magnetic field, an Young's modulus assessing method based on classical laminated plate theory is presented in this paper. Using the measured natural frequencies of Au, Cu, Cr, Al and SiC materials with various thicknesses in the literature, the Young's modulus of the five… More >

Hao-Miao Zhou^1,2, You-He Zhou¹, Xiao-Jing Zheng¹, Jing Wei³

CMC-Computers, Materials & Continua, Vol.12, No.3, pp. 237-250, 2009, DOI:10.3970/cmc.2009.012.237

Abstract From the viewpoint of energy, a general magnetoelastic coupling theory including magnetic forces and magnetostriction effects is proposed for deformable magnetized medium. Firstly, a Taylor series expansion of independent variables of stress and magnetization in the elastic Gibbs free energy function is applied to obtain a polynomial expression; and then based on the magnetoelastic coupling mechanism, appropriate transcendental functions are substituted for some terms in a polynomial constitutive relationship derived by way of substituting the polynomial Gibbs free energy function in thermodynamic equations to achieve a more compact magnetostrictive constitutive relationship. The numerical simulation exhibits that the predicted magnetostrictive strain… More >

S.H. Kwon¹, H.K. Lee²

CMC-Computers, Materials & Continua, Vol.12, No.3, pp. 197-222, 2009, DOI:10.3970/cmc.2009.012.197

Abstract The electromagnetic shielding effectiveness of steel fiber-reinforced mortar was numerically examined in this study. A series of numerical analysis on twenty-seven types of specimens of different diameters, lengths, and volume fractions of fibers were conducted using the FE program HFSS to investigate the effect of the dimensions of steel fibers and the amount of fibers added to the mortar on the shielding effectiveness. S-parameters of some specimens were experimentally measured by the free space method and the experimentally measured S-parameters were compared with those computed in order to verify the present numerical analysis method. It was found that smaller diameters… More >

Chien-Ching Ma^1,2, Wen-Cha Wu²

CMC-Computers, Materials & Continua, Vol.11, No.2, pp. 79-108, 2009, DOI:10.3970/cmc.2009.011.079

Abstract The two-dimensional problem of a planar transversely isotropic piezoelectric layered half-plane subjected to generalized line forces and edge dislocations in the layer is analyzed by using the Fourier-transform method and the series expansion technique. The full-field solutions for displacements, stresses, electrical displacements and electric fields are expressed in explicit closed forms. The complete solutions consist only of the simplest solutions for an infinite piezoelectric medium with applied loadings. It is shown in this study that the physical meaning of this solution is the image method. The explicit solutions include Green's function for originally applied loadings in an infinite piezoelectric medium… More >

I. Smojver¹, J. Sorić²

CMC-Computers, Materials & Continua, Vol.3, No.1, pp. 13-24, 2006, DOI:10.3970/cmc.2007.003.013

Abstract The paper addresses the problem of impact on layered fibre composites. The behaviour of composite laminates under impact loading is dependent not only on the velocity but also on the mass and geometry of the impactor. Using micromechanical Mori-Tanaka approach, mechanical properties of the laminate have been calculated utilizing the material constants of the fibre and matrix. General purpose FEM software ABAQUS has been modified by means of user written subroutines for modelling of composite laminate and rigid impactor. The kinematics of the impact has been simulated using transient dynamic analysis. Employing user defined multi point constraints, delamination zones have… More >

Aimin Jiang^1,2, Haojiang Ding²

CMC-Computers, Materials & Continua, Vol.3, No.1, pp. 1-12, 2006, DOI:10.3970/cmc.2007.003.001

Abstract This paper presents a development of the boundary contour method (BCM) for magneto-electro-elastic media. Firstly, the divergence-free of the integrand of the magneto- electro-elastic boundary element is proved. Secondly, the boundary contour method formulations are obtained by introducing linear shape functions and Green's functions (Computers & Structures, 82(2004):1599-1607) for magneto-electro-elastic media and using the rigid body motion solution to regularize the BCM and avoid computation of the corner tensor. The BCM is applied to the problem of magneto-electro-elastic media. Finally, numerical solutions for illustrative examples are compared with exact ones and those of the conventional boundary element method (BEM). The… More >

D. P. Ghosh¹, S. Gopalakrishnan²

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 213-228, 2004, DOI:10.3970/cmc.2004.001.213

Abstract Anhysteretic, coupled, linear and nonlinear constitutive relationship for magnetostrictive material is studied in this paper. Constitutive relationships of magnetostrictive material are represented through two equations, one for actuation and other for sensing, both of which are coupled through magneto-mechanical coefficient. Coupled model is studied without assuming any explicit direct relationship with magnetic field. In linear-coupled model, which is assumed to preserve the magnetic flux line continuity, the elastic modulus, the permeability and magneto-elastic constant are assumed as constant. In nonlinear-coupled model, the nonlinearity is decoupled and solved separately for the magnetic domain and mechanical domain using two nonlinear curves, namely… More >