Fernanda Gentil¹, Renato Natal Jorge², António Joaquim Mendes Ferreira³, Marco Parente⁴, Pedro Martins⁵, Eurico de Almeida⁶

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.1, pp. 45-56, 2009, DOI:10.3970/icces.2009.009.045

Abstract The interest in finite element method (FEM) concerning biomechanics has been increasing, in particular, to analyze the mechanical behavior of the human ear. In this work, a finite element model of the middle ear was made. A dynamic study based on a structural response to harmonic vibrations, for different sound pressure levels, applied on the eardrum, is presented using the ABAQUS program. The model includes different ligaments and muscle tendons with elastic and hyperelastic behavior of these supportive structure. The non-linear behavior of the ligaments and muscle tendons was considered, being the connection between ossicles More >

Shaw-Jyh Shin¹, Chen-Hung Huang², Y.C. Shiah³

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.1, pp. 83-104, 2009, DOI:10.3970/cmes.2009.040.083

Abstract Owing to the CTE (Coefficient of Thermal Expansion) mismatch among solder joints, IC (Integrated Circuit) chip, and PCB (Printed Circuit Board), electronic packages shall experience fatigue failure after going though a period of thermal cycling. As a major means to enhance the reliability of the solder joints, underfill is often dispensed to fill the gap between the die and the substrate. This study aims at investigating how the underfill may affect the thermal fatigue life of WLCSP (Wafer Level Chip Scale Package) by means of FEA (finite element analysis). In this study, the thermal fatigue More >

E.V. González¹, P. Maimí¹, A. Turon¹, P.P. Camanho², J. Renart¹

CMC-Computers, Materials & Continua, Vol.9, No.1, pp. 51-92, 2009, DOI:10.3970/cmc.2009.009.051

Abstract This paper presents the formulation of a tri-dimensional cohesive element implemented in a user-written material subroutine for explicit finite element analysis. The cohesive element simulates the onset and propagation of the delamination in advanced composite materials. The delamination model is formulated by using a rigorous thermodynamic framework which takes into account the changes of mixed-mode loading conditions. The model is validated by comparing the finite element predictions with experimental data obtained in interlaminar fracture tests under quasi-static loading conditions. More >

S.H. Kwon¹, H.K. Lee²

CMC-Computers, Materials & Continua, Vol.12, No.3, pp. 197-222, 2009, DOI:10.3970/cmc.2009.012.197

Abstract The electromagnetic shielding effectiveness of steel fiber-reinforced mortar was numerically examined in this study. A series of numerical analysis on twenty-seven types of specimens of different diameters, lengths, and volume fractions of fibers were conducted using the FE program HFSS to investigate the effect of the dimensions of steel fibers and the amount of fibers added to the mortar on the shielding effectiveness. S-parameters of some specimens were experimentally measured by the free space method and the experimentally measured S-parameters were compared with those computed in order to verify the present numerical analysis method. It More >

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 More >

A.B. Mahmud Hasan^1,2, M A Wahab¹, S.M. Guo¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 231-240, 2008, DOI:10.3970/sdhm.2008.004.231

Abstract This paper presents details analysis of Heat Affected Zone (HAZ) in High Temperature Vacuum Tube Furnace (HTVTF) to predict fracture region in tube wall due to thermal stress from temperature variation across its thickness. A simple mathematical model is used to illustrate stress concentration arising due to thermal stresses in tube wall and HAZs. Finite element model and analysis were carried out utilizing finite element analysis commercial codes. Combination of thermal stress due to temperature difference determine fracture region. Experimental and simulation results of inside temperature of tube are observed and similar relation have been More >

M. M. Rahman¹, A. K. Arrifin², M. J. M. Nor², S. Abdullah²

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 173-180, 2008, DOI:10.3970/sdhm.2008.004.173

Abstract This paper presents the fatigue analysis of spot-weld joints for automative structures to predict the lifetime and location of the weakest spot-welds due to the imposed loading conditions. A simple model was used to illustrate the technique of spot-weld fatigue analysis. Finite element model and analysis were carried out utilizing the finite element analysis commercial codes. Linear elastic finite element analysis was carried out to predict the stress state along the weld direction. It can be seen from the results that the predicted life greatly influence the sheet thickness, spot diameter and loading conditions of More >

Zdenko Tonković¹, Jurica Sorić^1,2, Ivica Skozrit¹

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.2, pp. 75-90, 2008, DOI:10.3970/cmes.2008.026.075

Abstract An efficient numerical algorithm for modeling of cyclic elastoplastic deformation of shell structures is derived. The constitutive model includes highly nonlinear multi-component forms of kinematic and isotropic hardening functions in conjunction with von Mises yield criterion. Therein, the closest point projection algorithm employing the Reissner-Mindlin type kinematic model, completely formulated in tensor notation, is applied. A consistent elastoplastic tangent modulus ensures high convergence rates in the global iteration approach. The integration algorithm has been implemented into a layered assumed strain isoparametric finite shell element, which is capable of geometrical nonlinearities including finite rotations. Numerical examples, More >

Amit Shaw¹, B. Banerjee¹, D Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 31-60, 2008, DOI:10.3970/cmes.2008.026.031

Abstract A generalization of a NURBS based parametric mesh-free method (NPMM), recently proposed by Shaw and Roy (2008), is considered. A key feature of this parametric formulation is a geometric map that provides a local bijection between the physical domain and a rectangular parametric domain. This enables constructions of shape functions and their derivatives over the parametric domain whilst satisfying polynomial reproduction and interpolation properties over the (non-rectangular) physical domain. Hence the NPMM enables higher-dimensional B-spline based functional approximations over non-rectangular domains even as the NURBS basis functions are constructed via the usual tensor products of… More >

L.M. Xu¹, H. Fan^2,3, X M Xie³, C. Li³

CMC-Computers, Materials & Continua, Vol.7, No.3, pp. 119-128, 2008, DOI:10.3970/cmc.2008.007.119

Abstract In the present study we performed finite element simulation for bi-continuous heterogeneous solids via a random distribution of materials to predict effective elastic properties. With a random distributing scheme, a statistical analysis via finite element becomes feasible for the multi-phase heterogeneous solids. Using a two-phase bi-continuous material as example, the numerical prediction of the effective properties is obtained in terms of a mean value and standard deviation with a sample size of 30 for each of given volume fraction. The finite element simulation results fall within the analytical bounds proposed by Hashin and Shtrikman (1963) More >