Ching-Chi Hsu¹, Jinn Lin², Yongyut Amaritsakul³, Takalamesar Antonius³, Ching-Kong Chao^3,4

CMC-Computers, Materials & Continua, Vol.11, No.1, pp. 1-14, 2009, DOI:10.3970/cmc.2009.011.001

Abstract Dynamic hip screw and gamma nail have been widely used to treat the patients with proximal femoral fractures, but clinical failures of those implants are still to be found. This study developed three-dimensional finite element models to investigate the biomechanical performances of the implants. Two kinds of commercially available implants (dynamic hip screw and gamma nail) and one newly designed implant (double screw nail) under three kinds of the proximal femoral fractures (neck fracture, subtrochanteric fracture, and subtrochanteric fracture with gap) were evaluated. Double screw nail showed better biomechanical performances than dynamic hip screw and gamma nail. Two commercially available… More >

Liviu Marin¹, Andreas Karageorghis²

CMC-Computers, Materials & Continua, Vol.10, No.3, pp. 259-294, 2009, DOI:10.3970/cmc.2009.010.259

Abstract We study the stable numerical identification of an unknown portion of the boundary on which a given boundary condition is provided and additional Cauchy data are given on the remaining known portion of the boundary of a two-dimensional domain for problems governed by either the Helmholtz or the modified Helmholtz equation. This inverse geometric problem is solved using the method of fundamental solutions (MFS) in conjunction with the Tikhonov regularization method. The optimal value for the regularization parameter is chosen according to Hansen's L-curve criterion. The stability, convergence, accuracy and efficiency of the proposed method are investigated by considering several… More >

B Keerthika¹, Y P Cao², D Raabe¹

CMC-Computers, Materials & Continua, Vol.10, No.3, pp. 243-258, 2009, DOI:10.3970/cmc.2009.010.243

Abstract In this study, effects of the plastic deformation and the time-dependent deformation behavior on the fundamental relations in the Oliver & Pharr method are studied by using finite element analysis based on a viscoelastic-plastic model developed for polymers. The study eventually yields an experimental protocol and using which, the instantaneous modulus of the viscoelastic-plastic materials may be reliably determined. Experiments have been performed on four polymers to verify the conclusions from the numerical analysis. More >

J.H. Tian^1,2, X. Han², S.Y. Long³, G.Q. Xie⁴

CMC-Computers, Materials & Continua, Vol.10, No.3, pp. 229-242, 2009, DOI:10.3970/cmc.2009.010.229

Abstract A heat conduction analysis of the functionally graded material (FGM) plates has been investigated based on the hybrid numerical method (HNM). HNM combines the layer element method with the method of Fourier transforms and proves to be efficient and reliable. The FGM plates are infinite large and the material properties vary continuously through thickness. The heat source continually acted one the FGM plates. The temperature distribution of the FGM plates is obtained in different time and different position. Some useful results for heat conduction problems are shown in figures. This article applies HNM to heat conduction firstly and provides us… More >

S. Mukherjee¹, S. Chakraborty², I. Manna^1,3

CMC-Computers, Materials & Continua, Vol.10, No.3, pp. 217-228, 2009, DOI:10.3970/cmc.2009.010.217

Abstract Influence of power density and interaction time for austenitisation during laser surface hardening of plain carbon eutectoid steel has been investigated. The analysis involves numerical prediction of thermal and solute diffusion profiles and thereby, the time needed for homogenization of austenite for different processing conditions. Experimental results provide qualitative validation. More >

P. B. Abhale¹, N. N. Viswanathan¹, N. B. Ballal¹

CMC-Computers, Materials & Continua, Vol.10, No.2, pp. 195-216, 2009, DOI:10.3970/cmc.2009.010.195

Abstract Simulation of gas flow in a multilayered non-isothermal packed bed is useful for blast furnace operators in deciding appropriate charging strategy. While using an anisotropic form of Ergun equation to simulate gas flow through such systems, a new solution methodology for non-isothermal gas with varying density flowing through a layered burden has been proposed. This involves handling non-linearity due to gas density variation with pressure and temperature by solving for the square of pressure instead of pressure directly and handling the non-linearity due to |v| term in the Ergun equation by solving linearized form of Ergun equation and updating |v|… More >

D.W. Kelly¹, M.C.W. Lee¹, A.C. Orifici^2,3, R.S.Thomson³, R. Degenhardt^4,5

CMC-Computers, Materials & Continua, Vol.10, No.2, pp. 163-194, 2009, DOI:10.3970/cmc.2009.010.163

Abstract An experimental program for collapse of curved stiffened composite shell structures encountered a wide range of initial and deep buckling mode shapes. This paper presents work to determine the significance of the buckling deformations for determining the final collapse loads and to understand the source of the variation. A finite element analysis is applied to predict growth of damage that causes the disbonding of stiffeners and defines a load displacement curve to final collapse. The variability in material properties and geometry is then investigated to identify a range of buckling modes and development of deep postbuckling deformation encountered in the… More >

Deepak A Apte¹, Ranjan Ganguli^1,2

CMC-Computers, Materials & Continua, Vol.10, No.2, pp. 139-162, 2009, DOI:10.3970/cmc.2009.010.139

Abstract The influence of electric field and temperature on power consumption of piezoelectric actuated integrated structure is studied by using a single degree of freedom mass-spring-damper system model coupled with a piezoactuator. The material lead zirconate titanate, is considered as it is capable of producing relatively high strains (e.g., 3000με). Actuators are often subject to high electric fields to increase the induced strain produced, resulting in field dependant piezoelectric coefficient d₃₁, dielectric coefficient ε₃₃ and dissipation factor δ. Piezostructures are also likely to be used across a wide range of temperatures in aerospace and undersea operations. Again, the piezoelectric properties can… More >

Yang Pu¹, Xiang Zhihai¹, Hu Xiasong², Li Guorong², Zhu Haili², Mao XiaoqinCen², Zhangzhi^1,3

CMC-Computers, Materials & Continua, Vol.10, No.2, pp. 117-138, 2009, DOI:10.3970/cmc.2009.010.117

Abstract This paper studies the influence of root reinforcement on shallow soil protection by using Finite Element (FE) method. Taking the root-soil composite as a periodic material, the homogenization method is used to construct a Representative Volume Element (RVE) that consists of roots and soil. This RVE is discretized by a two-dimensional (2-D) FE mesh, while special formulation is established so that this model is capable of describing three-dimensional (3-D) deformations when the strain is invariant along the fiber axis. The important effect of debonding on the interface between the fiber and the matrix is also considered by using a special… More >

Chein-Shan Liu¹

CMC-Computers, Materials & Continua, Vol.10, No.1, pp. 97-116, 2009, DOI:10.3970/cmc.2009.010.097

Abstract A new numerical method is proposed for solving the delay ordinary differential equations (DODEs) under multiple time-varying delays or state-dependent delays. The finite difference scheme is used to approximate the ODEs, which together with the initial conditions constitute a system of nonlinear algebraic equations (NAEs). Then, a Fictitious Time Integration Method (FTIM) is used to solve these NAEs. Numerical examples confirm that the present approach is highly accurate and efficient with a fast convergence. More >