M. Marin¹, S. R. Mahmoud^2,3, K. S. Al-Basyouni⁴

CMC-Computers, Materials & Continua, Vol.37, No.1, pp. 23-37, 2013, DOI:10.3970/cmc.2013.037.023

Abstract Taking advantage of the flexibility of Lagrange’s identity, we prove the uniqueness theorem and some continuous dependence theorems without recourse to any energy conservation law, or to any boundedness assumptions on the constitutive coefficients. Also, we avoid the use of positive definiteness assumptions on the constitutive coefficients, even if these results are related to the difficult mixed problem in elasticity of micromorphic bodies. More >

Leiting Dong^1,2, Salah H. Gamal³, Satya N. Atluri^2,4

CMC-Computers, Materials & Continua, Vol.37, No.1, pp. 1-21, 2013, DOI:10.3970/cmc.2013.037.001

Abstract In this paper, a simple and reliable procedure of stochastic computation is combined with the highly accurate and efficient Trefftz Computational Grains (TCG), for a direct numerical simulation (DNS) of heterogeneous materials with microscopic randomness. Material properties of each material phase, and geometrical properties such as particles sizes and distribution, are considered to be stochastic with either a uniform or normal probabilistic distributions. The objective here is to determine how this microscopic randomness propagates to the macroscopic scale, and affects the stochastic characteristics of macroscopic material properties. Four steps are included in this procedure: (1) using the Latin hypercube sampling,… More >

E. Ferretti¹

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 293-322, 2013, DOI:10.3970/cmc.2013.036.293

Abstract The Cell Method is applied in order to model the debonding mechanism in ceramic floor tiles subjected to positive thermal variation. The causes of thermal debonding, very usual in radiant heat floors, have not been fully clarified at the moment. There exist only a few simplified analytical approaches that assimilate this problem to an eccentric tile compression, but these approaches introduce axial forces that, in reality, do not exist. In our work we have abandoned the simplified closed form solution in favor of a numerical solution, which models the interaction between tiles and sub-base more realistically, when the positive thermal… More >

Zichun Yang^1,2,3, Gaohui Su^1,4, Fengrui Sun¹

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 271-292, 2013, DOI:10.3970/cmc.2013.036.271

Abstract In this paper, we investigate the radiative properties and the effective thermal conductivity (ETC) of the opacified silica aerogel by theoretical method. The radiative properties of the opacified silica aerogel are obtained by the modified Mie Scattering Theory that is used for particle scattering in absorbing medium. The modified gamma distribution is used to take account of the non-uniformity of the particle size. The solid thermal conductivity of the composite material is obtained by considering the scale effect of the particles. Based on these calculated thermophysical properties the coupled heat conduction and radiation through the evacuated opacified aerogel are solved… More >

Sanjeev Saxena¹, Raghvendra Singh², Geeta Agnihotri²

CMC-Computers, Materials & Continua, Vol.36, No.3, pp. 257-270, 2013, DOI:10.3970/cmc.2013.036.257

Abstract The present numerical study is an attempt to understand the dependency of characteristic distance on the fracture specimen thickness and temperature. The presented work will be useful to establish the characteristic distance prediction methodology using three dimensional FEM model. Based on the methods proposed for the numerical prediction of characteristic distance, it comes out that it depends on fracture specimen thickness and finally it converges after a specified thickness of fracture specimen. In Armco iron material, characteristic distance varies in temperature ranges where dynamic strain ageing phenomenon is observed, initially decrease and then increases again. More >

Ching-Feng Yu¹, Wen-Hwa Chen^1,2, Kun-Ling Chen¹, Hsien-Chie Cheng^2,3

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 203-229, 2013, DOI:10.3970/cmc.2013.036.203

Abstract The investigation assesses the thermal-mechanical and thermodynamic properties of various graphene sheets using a modified Nosé-Hoover (NH) thermostat method incorporated with molecular dynamics (MD) simulation. The investigation begins with an exploration of their thermal-mechanical properties at atmospheric pressure, including Young’s modulus, shear modulus, Poisson’s ratio, specific heats and linear and volumetric coefficients of thermal expansion (CTE). Two definitions of the line change ratio (ΔL/L) are utilized to determine the linear CTE of graphene sheets, and the calculations are compared with each other and data in the literature. To estimate the volumetric CTE values, the Connolly surface method is applied to… More >

Yao Hsu¹, Chih-Yen Su², Wen-Fang Wu^3,4

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 155-176, 2013, DOI:10.3970/cmc.2013.036.155

Abstract To study the fatigue reliability of a flip-chip chip scale package (FCCSP) subject to thermal cyclic loading, a Monte Carlo simulation-based parametric study is carried out in the present study. A refined procedure as compared with the recently released Probabilistic Design System (PDS) of ANSYS is proposed and employed in particular. The thermal-cyclic fatigue life of the package is discussed in detail since it is related directly to the reliability of the package. In consideration of the analytical procedure as well as real manufacturing processes, a few geometric dimensions and material properties of the package are assumed random. The empirical… 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 >

C.J. Huang¹, T.Y. Hung¹, K.N. Chiang²

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 99-133, 2013, DOI:10.3970/cmc.2013.036.099

Abstract The development in the field of nanotechnology has prompted numerous researchers to develop various simulation methods for determining the material properties of nanoscale structures. However, these methods are restricted by the speed limitation of the central processing unit (CPU), which cannot estimate larger-scale nanoscale models within an acceptable time. Thus, decreasing the CPU processing time and retaining the estimation accuracy of physical properties of nanoscale structures have become critical issues. Accordingly, this study aims to decrease the CPU processing time and complexity of large nanoscale models by utilizing, atomistic-continuum mechanics (ACM) to build an equivalent model of carbon nanotubes (CNTs).… More >

P. Yuvaraj¹, A. Ramachandra Murthy², Nagesh R. Iyer³, Pijush Samui⁴, S.K. Sekar⁵

CMC-Computers, Materials & Continua, Vol.36, No.1, pp. 73-97, 2013, DOI:10.3970/cmc.2013.036.073

Abstract This paper presents Multivariate Adaptive Regression Splines (MARS) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (GF), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). This paper also presents the details of development of MARS model to predict failure load (Pmax) of high strength concrete (HSC) and ultra high strength concrete (UHSC) beam specimens. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack… More >