K. Hashiguchi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.1, pp. 55-62, 2007, DOI:10.3970/cmes.2007.017.055

Abstract Constitutive equation describing the mechanical properties of material has to be formulated in an identical form independent of coordinate systems by which it is described even if there exist any mutual configuration and/or mutual rotation between the material and coordinate systems. This mechanical requirement is attained by describing rate variables as corotational rate tensors with objectivity in constitutive equations in rate form. Besides, in order to use the material-time derivative of yield condition as a consistency condition it has to be replaced to the corotational derivative. In this note a general corotational rate for tensors More >

R. Costa¹, J. Alfaiate²

Structural Durability & Health Monitoring, Vol.2, No.1, pp. 11-18, 2006, DOI:10.3970/sdhm.2006.002.011

Abstract In this paper a numerical simulation is performed on the behaviour of reinforced concrete beams, submitted to initial damage, subsequently strengthened with external steel plates bonded with epoxy. Modelling these structures requires the characterization of the behaviour of different materials as well as the connection between them. Fracture is modelled within the scope of a discrete crack approach, using a formulation in which strong discontinuities are embedded in the finite elements. In this approach, the displacement field is truly discontinuous and the jumps are non-homogeneous within each parent element [Alfaiate, Wells and Sluys (2000)]. More >

Shen Yubin¹, Xie Huicai^1,2, Den Wei¹

CMC-Computers, Materials & Continua, Vol.3, No.2, pp. 49-54, 2006, DOI:10.3970/cmc.2006.003.049

Abstract Bonding an overlay of new concrete onto the damaged concrete is a usual repair method. Because of the different shrinkage rate of the new and old concrete, restrained shrinkage cracks will appear in the new concrete. The cracks will reduce durability and strength of the repaired structure. A new repair method using an interface layer of carbon fiber reinforced cement mortar between new and old concrete was developed in this paper. The new method was found to be very effective in reducing shrinkage cracking of repaired beams and slabs. Comparing with normal repaired beams, the More >

S. N. Atluri¹

Structural Durability & Health Monitoring, Vol.1, No.1, pp. 1-20, 2005, DOI:10.3970/sdhm.2005.001.001

Abstract The solution of three-dimensional cracks (arbitrary surfaces of discontinuity) in solids and structures is considered. The BEM, developed based on the symmetric Galerkin BIEs, is used for obtaining the fracture solutions at the arbitrary crack-front. The finite element method is used to model the uncracked global (built-up) structure for obtaining the stresses in an otherwise uncracked body. The solution for the cracked structural component is obtained in an iteration procedure, which alternates between FEM solution for the uncracked body, and the SGBEM solution for the crack in the local finite-sized subdomain. In addition, some crack… More >

X. Neil Dong^1,2, Xiaohui Zhang¹, X. Edward Guo¹

Molecular & Cellular Biomechanics, Vol.2, No.2, pp. 63-68, 2005, DOI:10.3970/mcb.2005.002.063

Abstract In human cortical bone, cement lines (or reversal lines) separate osteons from the interstitial bone tissue, which consists of remnants of primary lamellar bone or fragments of remodeled osteons. There have been experimental evidences of the cement line involvement in the failure process of bone such as fatigue and damage. However, there are almost no experimental data on interfacial properties of cement lines in human cortical bone. The objective of this study is to design and assemble a precision and computer controlled osteon pushout microtesting system, and to experimentally determine the interfacial strength of cement… More >

Jin Yeon Cho¹, Jae Mo An², You Me Song¹, Seungsoo Lee¹, Dong Whan Choi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 1-18, 2005, DOI:10.3970/cmes.2005.009.001

Abstract A displacement welding technique is proposed to carry out coupled analysis of the integrated whole model which consists of independently modeled finite element substructures. In the proposed method, the incompatible displacement fields in the interfaces of independently modeled substructures are directly welded together through a blended function that is newly defined in the transient region of mismatching interface. To construct the blended function, the moving least squares function, which does not require well-defined nodal connectivity, is utilized along with the original finite element shape function. The meshless character of the moving least squares function makes More >

Alexandre S. Botta¹, Wilson S. Venturini²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.1, pp. 15-28, 2005, DOI:10.3970/cmes.2005.008.015

Abstract In this work a regularized boundary-finite element combination is proposed to analyse 2D elastostatic solids reinforced by fibres. The boundary element is adopted to model the matrix behaviour, while finite elements model the embedded fibres. The debonding effects caused by the adherence loss between the two materials are also considered. A three-degree polynomial is adopted to approach the displacement field along the fibre elements, while linear approximations are used to represent the bonding forces between fibres and the matrix. The non-linear debonding model is governed by a loading function written in terms of the contact More >

Hiroshi Okada¹

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.3, pp. 185-186, 2005, DOI:10.3970/cmes.2005.010.185

Abstract This article has no abstract. More >

Y. Bei¹, B.J. Fregly¹, W.G. Sawyer¹, S.A. Banks^1,2, N.H. Kim¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.2, pp. 145-152, 2004, DOI:10.3970/cmes.2004.006.145

Abstract Mild wear of ultra-high molecular weight polyethylene tibial inserts continues to affect the longevity of total knee replacements (TKRs). Using static finite element and elasticity analyses, previous studies have hypothesized that polyethylene wear can be reduced by using a thicker tibial insert to decrease contact pressures. To date, no study has taken this hypothesis to the next step by performing dynamic analyses under in vivo functional conditions to quantify the relationship between contact pressures, insert thickness, and mild wear. This study utilizes multibody dynamic simulations incorporating elastic contact to perform such analyses. \textit {In vivo} fluoroscopic… More >

H.J. Bohm¨ ¹, W. Han^1,2, A. Eckschlager^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 5-20, 2004, DOI:10.3970/cmes.2004.005.005

Abstract Three-dimensional periodic micromechanical models are used for studying the mechanical behavior of discontinuously reinforced ductile matrix composites. The models are based on unit cells that contain a number of randomly positioned and, where applicable, randomly oriented spherical, spheroidal or cylindrical reinforcements. The Finite Element method is used to resolve the microscale stress and strain fields and to predict the homogenized responses under overall uniaxial tensile loading in the elastic and elastoplastic regimes. Periodicity boundary conditions are employed in the analyses.\\ The main emphasis of the contribution is put on studying the microscale stresses in the More >