M.A.Arafin¹, J.A.Szpunar²

CMC-Computers, Materials & Continua, Vol.14, No.2, pp. 125-140, 2009, DOI:10.3970/cmc.2009.014.125

Abstract A novel microstructure, texture and grain boundary character based model has been proposed to simulate the intergranular crack propagation behavior in textured polycrystalline materials. The model utilizes the Voronoi algorithm and Monte Carlo simulations to construct the microstructure with desired grain shape factor, takes the texture description of the materials to assign the orientations of the grains, evaluates the grain boundary character based on the misorientation angle - axis calculated from the orientations of the neighboring grains, and takes into account the inclination of grain boundaries with respect to the external stress direction. Markov Chain theory has been applied to… More >

Xiaohua Hu¹, Gordana A. Cingara¹, David S. Wilkinson¹, Mukesh Jain², PeidongWu², Raja K. Mishra³

CMC-Computers, Materials & Continua, Vol.14, No.2, pp. 99-124, 2009, DOI:10.3970/cmc.2009.014.099

Abstract This work aims to understand the texture distribution in the localized necking band formed during uni-axial tension of AA5754 using an edge-constrained, plane strain post-necking FE model. The model domain is a long cross section of the band. Initial grain structure is mapped into the mesh from EBSD data using a modified Voroni-cell interpolation and considering pre-straining prior to localized necking. The material points in grains are assumed to exhibit isotropic elastoplastic behavior but have a relative strength in terms of Taylor factors which are updated by a Taylor-Bishop-Hill model. The predicted textures and gradients within the localized necking band… More >

H. Elnaiem¹, D. Casimir¹, P. Misra¹, S.M. Gatica^1,2

CMC-Computers, Materials & Continua, Vol.14, No.1, pp. 23-34, 2009, DOI:10.3970/cmc.2009.014.023

Abstract Nanobubbles have been found to form at the interface of water and solid surfaces. We examine the conditions for such bubbles to form and estimate the pressure inside the bubble based on thermodynamic considerations. Using a simple model we calculate the contact angle for a wide range of temperatures and hypothetical substrates possessing a continuous range of strengths. We show that as the temperature increases the shape of a bubble changes continuously from a spherical cap with low curvature to a complete sphere. An equivalent effect results from either increasing the strength of the solid or decreasing the surface tension.… More >

D.P.Mondal¹, S.Das¹, Anshul Badkul¹, Nidhi Jha¹

CMC-Computers, Materials & Continua, Vol.13, No.2, pp. 115-134, 2009, DOI:10.3970/cmc.2009.013.115

Abstract The cooling effect by evaporative liquid is modeled by considering that heat is transferred from the system to the surrounding due to evaporation of liquid through the pores present in the medium. The variation of cooling rate with cell size, volume fraction of pores and physical conditions has been analyzed. The model demonstrates that it increases with increase in thickness of the foam slab and with increase in velocity of air. It is also observed that cooling effect decreases with decrease in volume fraction of porosity and with increase in relative density, cell size, thermal conductivity and relative humidity. More >

De-Shin Liu¹, Zhen-Wei Zhuang^1,2, Cho-LiangChung³, Ching-Yang Chen⁴

CMC-Computers, Materials & Continua, Vol.13, No.2, pp. 89-114, 2009, DOI:10.3970/cmc.2009.013.089

Abstract This paper employs a novel numerical technique, designated as the hybrid moisture element method (HMEM), to model and analyze moisture diffusion in a heterogeneous epoxy resin containing multiple randomly distributed particles. The HMEM scheme is based on a hybrid moisture element (HME), whose properties are determined by equivalent moisture capacitance and conductance matrixes calculated using the conventional finite element formulation. A coupled HME-FE scheme is developed and implemented using the commercial FEM software ABAQUS. The HME-FE scheme is then employed to analyze the moisture diffusion characteristics of a heterogeneous epoxy resin layer containing particle inclusions. The analysis commences by comparing… More >

W.F.Yuan¹, K.H.Tan ¹

CMC-Computers, Materials & Continua, Vol.13, No.1, pp. 49-62, 2009, DOI:10.3970/cmc.2009.013.049

Abstract A simple cellular automaton (CA) scheme is proposed to simulate heat conduction in anisotropic domains. The CA is built on random nodes rather than an irregular grid. The local rule used in the CA is defined by physical concepts instead of differential equations. The accuracy of the proposed approach is verified by classical examples. As an application of the proposed method, the CA approach is incorporated into fibre model which is widely used in finite element analysis to calculate the temperature distribution on the cross-section of composite beams. Numerical examples demonstrate that the proposed scheme can be conveniently applied to… More >

J.A.Ferreira^1,2, P. de Oliveira², P. da Silva³, D. M. G. Comissiong⁴

CMC-Computers, Materials & Continua, Vol.13, No.1, pp. 17-48, 2009, DOI:10.3970/cmc.2009.013.017

Abstract A phenomenological formulation is adopted to investigate desorption in polymers. The speed of the front is studied and the well-posedness of the general model is analyzed. Numerical simulations illustrating the dynamics of the desorption process described by the proposed model are included. More >

Shu-Feng Lee¹, Che-Wun Hong^1,2

CMC-Computers, Materials & Continua, Vol.12, No.3, pp. 223-236, 2009, DOI:10.3970/cmc.2009.012.223

Abstract Solid oxides, such as ceria (CeO₂) doped with cations of lower valance, are potential electrolytes for future solid oxide fuel cells. This is due to the theoretically high ionic conductivity at low operation temperature. This paper investigates the feasibility of two potential electrolytes which are samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) to replace the traditional yttria-stablized zirconia (YSZ). Molecular simulation techniques were employed to study the influence of different dopant concentrations at different operation temperatures on the ionic conductivity from the atomistic perspective. Simulation results show that the optimized ionic conductivity occurs at 11.11mol% concentration using both dopants of… More >

José Pedro Rino¹,Giovano de Oliveira Cardozo¹, Adalberto Picinin¹

CMC-Computers, Materials & Continua, Vol.12, No.2, pp. 145-156, 2009, DOI:10.3970/cmc.2009.012.145

Abstract A new parametrization for the previous empirical interatomic potential for indium antimonite is presented. This alternative parametrization is designed to correct the energetic sequence of structures. The effective empirical interatomic potential proposed consists of two and three body interactions which has the same functional form of the interatomic potential proposed by Vashishta et. al. to study other semiconductors (Branicio et al., 2003; Ebbsjo et al., 2000; Shimojo et al., 2000; Vashishta et al., 2008). Molecular dynamics simulations (MD) are performed to study high pressure phases of InSb up to 70 GPa and its thermal conductivity as a function of temperature.… More >

Amiya K. Samanta¹, Somnath Ghosh²

CMC-Computers, Materials & Continua, Vol.12, No.1, pp. 1-38, 2009, DOI:10.3970/cmc.2009.012.001

Abstract This paper presents a formulation of hypo-elasticity based RC beam model with bond-slip. Details of the constitutive model and analysis method used are provided. A procedure has been described to carry out three-dimensional analysis considering both geometrical as well as material nonlinearity for a simply supported RC beam employing finite element technique, which uses 8-noded isoparametric hexahedral element HCiS18. Enhanced assumed strain (EAS) formulation has been utilized to predict load-deformation and internal stresses both in the elastic as well as nonlinear regime. It models the composite behaviour of concrete and reinforcements in rigid /perfect bond situation and their mutual interaction… More >