T.Y. Wu¹, W.C. Tsai², J.J. Lee²

CMC-Computers, Materials & Continua, Vol.17, No.3, pp. 175-214, 2010, DOI:10.3970/cmc.2010.017.175

Abstract The crushing of cellular materials is a highly nonlinear problem, for which geometrical, material, and contact/impact must be treated in one analysis. In order to develop a framework able to solve it efficiently and accurately, in this paper procedures for in-plane crushing analysis of cellular materials using vector form intrinsic finite element (VFIFE) is performed. A beam element of VFIFE is employed to handle large rotation and large deflection in the cell walls. An elastic-plastic material model with mixed hardening rule is adopted to account for material nonlinearity. In addition, an efficient contact/impact algorithm is designed to treat the complex… More >

Surkay D. Akbarov^1,2, Resat Kosker³, Yasemen Ucan³

CMC-Computers, Materials & Continua, Vol.17, No.2, pp. 77-102, 2010, DOI:10.3970/cmc.2010.017.077

Abstract In the framework of the piecewise homogeneous body model with the use of the three-dimensional geometrically non-linear exact equations of the theory of elasticity, the method for determination of the stress-strain state in the infinite body containing periodically located row of periodically curved fibers is developed. It is assumed that the midlines of the fibers are in the same plane. With respect to the location of the fibers according to each other the sinphase and antiphase curving cases are considered. Numerical results on the effect of the geometrical non-linearity to the values of the self balanced shear and normal stresses… More >

Taotao Hu¹, gping Shen^1,2

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 41-58, 2010, DOI:10.3970/cmc.2010.017.041

Abstract In this paper, an axisymmetric indentation model is set up to calculate the effects of the roughness of the thermally grown oxide (TGO) layer, which was modeled as a sinusoidal wave, on the indentation response of the thermal barrier coatings. It is found that the amplitude, wavelength, and thickness of the thermally grown oxide layer have obvious influences on the indentation response, while the effect of the indenter position can be neglected. In the top coating layer, residual stress mainly occurs below the indenter and around the nearest two peaks of the thermally grown oxide layer to the indenter. Only… More >

Chih-Wen Chang¹, Chein-Shan Liu²

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 19-40, 2010, DOI:10.3970/cmc.2010.017.019

Abstract In this study, we employ a semi-analytical approach to solve a two-dimensional advection-dispersion equation (ADE) for identifying the contamination problems. First, the Fourier series expansion technique is used to calculate the concentration field C(x, y, t) at any time t < T. Then, we ponder a direct regularization by adding an extra termaC(x, y, 0) on the final time data C(x, y, T), to reach a second-kind Fredholm integral equation. The termwise separable property of kernel function allows us obtaining a closed-form solution of the Fourier coefficients. A strategy to choose the regularization parameter is offered. The solver utilized in… More >

S. Patala¹, C.A. Schuh¹

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.017.001

Abstract Recent advances in microstructural characterization have made it possible to measure grain boundaries and their networks in full crystallographic detail. Statistical studies of the complete boundary space using full crystallographic parameters (misorientations and boundary plane inclinations) are limited because the topology of the parameter space is not understood (especially for homophase grain boundaries). This paper addresses some of the complexities associated with the group space of grain boundaries, and resolves the topology of the complete boundary space for systems of two-dimensional crystals. Although the space of homophase boundaries is complicated by the existence of a `no-boundary' singularity, i.e., no boundary… More >

Zone-Ching Lin¹and Ren-Yuan Wang¹

CMC-Computers, Materials & Continua, Vol.16, No.3, pp. 247-272, 2010, DOI:10.3970/cmc.2010.016.247

Abstract The paper establishes a new three-dimensional quasi-steady molecular statics nanoscale abrasive cutting model to investigate the abrasive cutting behavior in the downpressing and abrasive cutting process of a workpiece in chemical mechanical polishing (CMP) process. The downpressing and abrasive cutting process is a continuous process. The abrasive cutting process is done after the single abrasive particle has downpressed and penetrated a workpiece to a certain depth of a workpiece. The paper analyzes the effects of the abrasive particles with different diameters on action force. It also analyzes the action force change of abrasive particles with different diameters on the projected… More >

Xue-Qian Fang^1,2, Xiao-Hua Wang¹, Le-Le Zhang³

CMC-Computers, Materials & Continua, Vol.16, No.3, pp. 229-246, 2010, DOI:10.3970/cmc.2010.016.229

Abstract In the design of advanced micro- and nanosized materials and devices containing inclusions, the effects of surfaces/interfaces on the stress concentration become prominent. In this paper, based on the surface/interface elasticity theory, a two-dimensional problem of an elliptical nano-inhomogeneity under anti-plane shear waves is considered. The conformal mapping method is then applied to solve the formulated boundary value problem. The analytical solutions of displacement fields are expressed by employing wave function expansion method, the expanded mode coefficients are determined by satisfying the boundary conditions at the interfaces of the nano-inhomogeneity. Analyses show that the effect of the interfacial properties on… More >

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 >

Veturia Chiroiu¹, Ligia Munteanu¹, Pier Paolo Delsanto²

CMC-Computers, Materials & Continua, Vol.16, No.1, pp. 75-100, 2010, DOI:10.3970/cmc.2010.016.075

Abstract Conventional continuum theories are unable to capture the observed indentation size effects, due to the lack of intrinsic length scales that represent the measures of nanostructure in the constitutive relations. In order to overcome this deficiency, the Toupin-Mindlin strain gradient theory of nanoindentation is formulated in this paper and the size dependence of the hardness with respect to the depth and the radius of the indenter for multiple walled carbon nanotubes is investigated. Results show a peculiar size influence on the hardness, which is explained via the shear resistance between the neighboring walls during the buckling of the multiwalled nanotubes. More >

J. Zidek¹ , J. Kucera¹, J. Jancar¹

CMC-Computers, Materials & Continua, Vol.16, No.1, pp. 51-74, 2010, DOI:10.3970/cmc.2010.016.051

Abstract It has been shown that in particulate filled composites, a cross-property relationship exists between various transport properties (e.g., electrical conductivity, mechanical reinforcement, gas permeation) of a macroscale composite. Thus, knowledge of the effective mechanical properties of a composite immediately places bounds on its electrical conductivity or gas permeation behavior. Using these bounds allows us to predict the phase dispersion state that optimizes one or multiple properties of the composite and, thus, the knowledge of how spatial arrangement of filler particles at their given content affects physical properties of the composite can be valuable. In this paper, a new numerical model… More >