L. Godinho A. ¹, A. Tadeu¹, P. Amado Mendes¹

CMC-Computers, Materials & Continua, Vol.5, No.2, pp. 117-128, 2007, DOI:10.3970/cmc.2007.005.117

Abstract This paper presents a strategy for using the Method of Fundamental Solutions (MFS) to model the propagation of elastic waves around thin structures, like empty cracks or thin rigid screens, located in a homogeneous elastic medium. The authors make use of a simple approach for modeling these propagation conditions using the MFS together with decomposition of the domain into distinct regions. This approach makes it possible to avoid the undetermined system of equations that arises from imposing boundary conditions at both sides of a thin structure. The numerical implementation of the MFS is performed in… More >

Jin Yeon Cho¹

CMC-Computers, Materials & Continua, Vol.5, No.2, pp. 99-116, 2007, DOI:10.3970/cmc.2007.005.099

Abstract A novel way is proposed to fulfill Kronecker delta condition in moving least squares (MLS) approximation along the essential boundary. In the proposed scheme, the original MLS weight is modified to boundary interpolatable (BI) weight based on the observation that the support of weight function is exactly the same as the support of MLS nodal shape function. The BI weight is zero along the boundary edges except the edges containing the nodal point associated with the concerned weight. In order to construct the BI weight from the original weight, concept of edge distance function is… More >

Kanchi Venkatesulu Reddy¹, Ranjan Ganguli²

CMC-Computers, Materials & Continua, Vol.5, No.2, pp. 79-98, 2007, DOI:10.3970/cmc.2007.005.079

Abstract This paper investigates the effect of damage on beams with fixed boundary conditions using Fourier analysis of the mode shapes in spatial domain. A finite element model is used to obtain the mode shapes of a damaged fixed-fixed beam. Then the damaged beams are studied using a spatial Fourier analysis. This approach contrasts with the typical time domain application of Fourier analysis for vibration problems. It is found that damage causes considerable change in the Fourier coefficients of the mode shapes. The Fourier coefficients, especially the higher harmonics, are found to be sensitive to both More >

N. Mai-Duy¹, A. Khennane², T. Tran-Cong³

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 63-78, 2007, DOI:10.3970/cmc.2007.005.063

Abstract This paper reports a meshless method, which is based on radial-basis-function networks (RBFNs), for the static analysis of moderately-thick laminated composite plates using the first-order shear deformation theory. Integrated RBFNs are employed to represent the field variables, and the governing equations are discretized by means of point collocation. The use of integration rather than conventional differentiation to construct the RBF approximations significantly stabilizes the solution and enhances the quality of approximation. The proposed method is verified through the solution of rectangular and non-rectangular composite plates. Numerical results obtained show that the method achieves a very More >

M.V.V.S. Murthy¹, S. Gopalakrishnan^2,3, P.S. Nair⁴

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 43-62, 2007, DOI:10.3970/cmc.2007.005.043

Abstract A refined 2-node, 7 DOF/node beam element formulation is presented in this paper. This formulation is based on higher order shear deformation theory with lateral contraction for axial-flexural-shear coupled deformation in asymmetrically stacked laminated composite beams. In addition to axial, transverse and rotational degrees of freedom, the formulation also incorporates the lateral contraction and its higher order counterparts as degrees of freedom. The element shape functions are derived by solving the static part of the governing equations. The element considers general ply stacking and the numerical results shows that the element exhibits super convergent property. More >

Chein-Shan Liu^1,2

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 31-42, 2007, DOI:10.3970/cmc.2007.005.031

Abstract By using a meshless regularized integral equation method (MRIEM), the solution of elastic torsion problem of a uniform bar with arbitrary cross-section is presented by the first kind Fredholm integral equation on an artificial circle, which just encloses the bar's cross-section. The termwise separable property of kernel function allows us to obtain the semi-analytical solutions of conjugate warping function and shear stresses. A criterion is used to select the regularized parameter according to the minimum principle of Laplace equation. Numerical examples show the effectiveness of the new method in providing very accurate numerical solutions as More >

A. H. Muhr¹

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 11-30, 2007, DOI:10.3970/cmc.2007.005.011

Abstract The mechanics of laminates of elastomer and shims of high modulus material are reviewed. Such structures are often built to provide engineering components with specified, and quite different, stiffnesses in different modes of deformation. The shims may either be rigid or flexible, flat or curved, but are usually close to inextensible, being made of a high modulus material such as steel. On the other hand, rubber has an exceptionally low shear modulus, about one thousandth of its bulk modulus, so that shear of the rubber layers and flexure of the high modulus layers (if thin)… More >

Ramana M. Pidaparti^1,2, Evan J. Neblett²

CMC-Computers, Materials & Continua, Vol.5, No.1, pp. 1-10, 2007, DOI:10.3970/cmc.2007.005.001

Abstract A neural network (NN) model is developed for the analysis and prediction of the mapping between degradation of chemical elements and electrochemical parameters during the corrosion process. The input parameters to the neural network model are alloy composition, electrochemical parameters, and corrosion time. The output parameters are the degradation of chemical elements in AA 2024-T3 material. The NN is trained with the data obtained from Energy Dispersive X-ray Spectrometry (EDS) on corroded specimens. A very good performance of the neural network is achieved after training and validation with the experimental data. After validating the NN More >

E. A. Semma¹, M. El Ganaoui², V. Timchenko³, E. Leonardi³

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.3, pp. 191-202, 2006, DOI:10.3970/fdmp.2006.002.191

Abstract This paper deals with the investigation of thermovibrational convection induced by harmonic oscillations of the temperature boundary conditions related to the hot wall in a Bridgman-like (VB) geometrical configurations. Two different models of the VB configuration are considered (a simplified version referred to as "restricted" model and a more realistic and complete model with phase change allowed). The effects of temperature modulation are considered for both models and with regard to several possible initial (basic) states (stationary and oscillatory). In the restricted fluid cavity, we identify the existence of a critical frequency minimizing the flow More >

T. J. Jaber¹, M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.3, pp. 175-190, 2006, DOI:10.3970/fdmp.2006.002.175

Abstract The study deals with three-dimensional numerical simulations of fluid flow and heat transfer under the effect of a rotating magnetic field (RMF) during the growth of Ge_0.98Si_0.02 by the traveling solvent method (TSM). By using a RMF, an attempt is made to suppress buoyancy convection in the Ge_0.98Si_0.02 solution zone in order to get high quality and homogeneity with a flat growth interface. The full steady-state Navier-Stokes equations, as well as the energy, mass transport and continuity equations, are solved numerically using the finite element method. Different magnetic field intensities (B=2, 4, 10, 15 and 22 More >