S.H. Pyo¹, H.K. Lee^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.3, pp. 271-306, 2009, DOI:10.3970/cmes.2009.040.271

Abstract This paper presents a micromechanical approach for predicting the elastic and multi-level damage response of aligned and randomly oriented whisker-/ short fiber-reinforced composites. Based on a combination of Eshelby's micromechanics and the evolutionary imperfect interface approach, the effective elastic moduli of the composites are derived explicitly. The modified Eshelby's tensor for spheroidal inclusions with slightly weakened interface [Qu (1993b)] is extended in the present study to model whiskers or short fibers having mild or severe imperfect interfaces. Aligned and random orientations of spheroidal reinforcements are considered. A multi-level damage model in accordance with the Weibull's More >

K.H. Chen^1,2, J.H. Kao³, J.T. Chen⁴

CMC-Computers, Materials & Continua, Vol.9, No.3, pp. 253-280, 2009, DOI:10.3970/cmc.2009.009.253

Abstract In this paper, solving antiplane piezoelectricity problems with multiple inclusions are attended by using the regularized meshless method (RMM). This is made possible that the troublesome singularity in the MFS disappears by employing the subtracting and adding-back techniques. The governing equations for linearly electro-elastic medium are reduced to two uncoupled Laplace's equations. The representations of two solutions of the two uncoupled system are obtained by using the RMM. By matching interface conditions, the linear algebraic system is obtained. Finally, typical numerical examples are presented and discussed to demonstrate the accuracy of the solutions. 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 >

Dein Shaw^1,2, Chih-Ren Huang², Li-Cheng Huang²

CMC-Computers, Materials & Continua, Vol.11, No.3, pp. 229-242, 2009, DOI:10.3970/cmc.2009.011.229

Abstract In this study, a method for designing an in-plane, free-form, beam-type spring for use in a lower-limb orthosis was developed. A spring designed by this method follows a predefined relationship between loading and displacement. To facilitate the analysis of the spring, it was divided into several beam segments. The stiffness equations related to loading (including moment and force) and displacements (linear and rotation) of each beam segment were found to follow a modified (non-linear) Castigliano's second theorem (NCST) and were assembled by using the continuity of nodal points of neighbouring curve segments. Using the proposed… More >

E.J. Sapountzakis¹, V.G. Mokos²

CMC-Computers, Materials & Continua, Vol.10, No.1, pp. 1-40, 2009, DOI:10.3970/cmc.2009.010.001

Abstract In this paper the boundary element method is employed to develop a displacement solution for the general transverse shear loading problem of composite beams of arbitrary constant cross section. The composite beam (thin or thick walled) consists of materials in contact, each of which can surround a finite number of inclusions. The materials have different elasticity and shear moduli and are firmly bonded together. The analysis of the beam is accomplished with respect to a coordinate system that has its origin at the centroid of the cross section, while its axes are not necessarily the… More >

Richard W. Casey¹, Jack Barkin²

Canadian Journal of Urology, Vol.15, Suppl.4, pp. 71-77, 2008

Abstract Testosterone replacement therapy (TRT) can have signifi cant benefi cial effects in the appropriate hypogonadal male patient. Testosterone defi ciency is common in primary care practice and recognition of the signs and symptoms of this abnormality will allow physicians to choose appropriate interventions. The symptoms of clinical hypogonadism include muscle weakness, fatigue, mood changes and a reduced libido. Signs include a reduced muscle mass, osteoporosis, anemia and increased adiposity.
While routine screening for testosterone defi ciency, determination of testosterone levels in high risk populations, including obesity and diabetes, will help the clinician direct TRT to More >

Gregory R. Hanson, Lester S. Borden, Jr., Doug D. Backous, Stephen W. Bayles, John M. Corman

Canadian Journal of Urology, Vol.15, No.2, pp. 3990-3993, 2008

Abstract Introduction: With nerve-sparing techniques, patients undergoing a radical prostatectomy may avoid the morbidity of erectile dysfunction. Certain patients who are not candidates for nerve-sparing procedures may be eligible for nerve interposition grafts. While bilateral cavernosal nerve grafting after radical prostatectomy has shown efficacy, the effect of unilateral nerve grafting following prostatectomy remains unclear. We evaluate a large group of patients who underwent a unilateral cavernosal nerve replacement.
Methods: Forty patients underwent unilateral nerve sparing surgery with concomitant contralateral cavernosal nerve replacement. Patients were selected for this procedure based upon preoperative nomogram risk assessment, endorectal MRI evidence… More >

K. Lee¹ and S.W. Lee ²

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.3, pp. 253-272, 2008, DOI:10.3970/cmes.2008.034.253

Abstract A geometrically nonlinear assumed strain formulation is used to develop a nine-node solid shell element with quadratic displacement through the thickness. The transversely quadratic element allows direct use of the constitutive equations developed for three-dimensional solids, which is convenient when material nonlinearity is involved. The nodal degrees of freedom associated with the quadratic terms in the assumed displacement through the thickness are statically condensed out at the element level. The results of numerical tests conducted on selected example problems demonstrate the validity and effectiveness of the present approach. For the cases involving linear elastic material, More >

Y. C. Shiah¹, C. L. Tan², V.G. Lee³

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.3, pp. 205-226, 2008, DOI:10.3970/cmes.2008.034.205

Abstract The main impediment to the development of efficient algorithms for the stress analysis of 3D generally anisotropic elastic solids using the boundary element method (BEM) and the local boundary integral equation (LBIE) meshless method over the years is the complexity of the fundamental solutions and the computational burden to evaluate them. The ability to analytically simplify and reduce them into as explicit a form as possible so that they can be directly computed will offer significant cost savings. In addition, they facilitate easy implementation using existing numerical algorithms with the above-mentioned methods that have been More >

C.E. Majorana¹, V.A. Salomoni

CMES-Computer Modeling in Engineering & Sciences, Vol.33, No.1, pp. 49-84, 2008, DOI:10.3970/cmes.2008.033.049

Abstract A dynamic analysis of a thin shell finite element undergoing large displacements and rotations is here presented. The constitutive model adopted derives from the coupling of an hyperelastic basic model fulfilling a De Saint Venant-Kirchhoff criterion with a scalar damage function depending on the maximum value of a suitable strain measure attained through the deformation history; then plastic effects are included using an isotropic/kinematic hardening law. A conservative time integration scheme for the non-linear dynamics of the hyperelastic damaged-plastic thin shell is applied. The main characteristic of the scheme is to be conservative, since it More >