Baolin Wang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.2, pp. 81-84, 2008, DOI:10.3970/icces.2008.008.081

Abstract When the size of a physical system is smaller than its characteristic dimensions, the macroscopic viewpoint may not be applicable. In addition, experiments at micro/nanometer scale are difficult and the analysis of nano-experimental data is far from simple. This is mostly due to the lack of effective models that are able to study the structural characteristics and mechanics behavior of the micro/nanometer physical systems. Atomic simulation simulation has been used extensively in the investigation of nanoscale phenomena. However, the size limit of atomic simulation is far short to reach the macroscale because of the limitation More >

G. Papaioannou¹, G. Nianios¹, C. Mitroyiannis¹, S.Tashman², K.H. Yang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 7-12, 2008, DOI:10.3970/icces.2008.008.007

Abstract Little is known about in vivo menisci loads and displacements in the knee during strenuous activities. We have developed a method that combines biplane high-speed dynamic radiography (DRSA) and a subject-specific finite element model for studying in vivo meniscal behavior. In a very controlled uniaxial compression loading condition, removing of the pressure sensor from the model can result in relatively large errors in contact and cartilage stress that are not reflected in the change of meniscal displacement. More >

L. Gornet¹, S. Marguet², G. Marckmann³

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 63-74, 2006, DOI:10.3970/cmc.2006.004.063

Abstract The purpose of the present study is to determine the components of the effective elasticity tensor and the failure properties of Nomex^® honeycomb cores. In order to carry out this study, the NidaCore software, a program dedicated to Nomex®Cores predictions, has been developed using the Finite Element tool Cast3M-CEA. This software is based on periodic homogenization techniques and on the modelling of structural instability phenomena. The homogenization of the periodic microstructure is realized thanks to a strain energy approach. It assumes the mechanical equivalence between the microstructures of a RVE and a similar homogeneous macroscopic volume.… More >

M. S. Alam¹, M.A. Wahab^1,2

Structural Durability & Health Monitoring, Vol.1, No.3, pp. 171-184, 2005, DOI:10.3970/sdhm.2005.001.171

Abstract Fatigue life of curved structural joints in ship structures under constant amplitude cyclic loading has been studied in this research. A new approach for the simulation of fatigue crack growth in welded joints has been developed and the concept has been applied to welded curved butt-joints. The phenomena of crack propagation and interface debonding can be regarded as the formation of new surfaces. Thus, it is possible to model these problems by introducing the mechanism of surface formation. In the proposed method, the formation of new surface is represented by interface element based on the… More >

W. J. Ferguson¹, B. Palananthakumar²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.3, pp. 201-216, 2005, DOI:10.3970/cmes.2005.008.201

Abstract Environmental and safety issues associated with landfill gas require the control of off-site migration. Mathematical modelling can assist in the understanding of the processes and mechanisms controlling gas migration from municipal waste disposal sites. This paper presents the development and application of a mathematical model that simulates landfill gas migration within a partially saturated soil. This model accounts for two-phase flow and incorporates multi-component (methane, carbon dioxide, dry air and moisture) transport in the gas and liquid phases together with concomitant heat migration. The governing system of fully coupled non-linear partial differential equations of the… More >

R.H. Moore¹, S. Saigal²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 283-292, 2005, DOI:10.3970/cmes.2005.007.283

Abstract An efficient method for treating slivers and other poorly shaped elements in finite element solutions is presented. A major difficulty for finite element analyses arises from the creation of slivers in automated mesh generation. Sliver shaped elements can degrade the accuracy of a solution and are difficult to remove from a mesh. The proposed method treats slivers by first merging them with neighboring elements to form polyhedra and next subdividing the polyhedra into well-shaped tetrahedral elements. The method does not require the cumbersome and expensive operations of addition or rearrangement of nodes. The validity and More >

Morakot Likhitpanichkul¹, X. Edward Guo², Van C. Mow^1,3

Molecular & Cellular Biomechanics, Vol.2, No.4, pp. 191-204, 2005, DOI:10.3970/mcb.2005.002.191

Abstract Thorough analyses of the mechano-electrochemical interaction between articular cartilage matrix and the chondrocytes are crucial to understanding of the signal transduction mechanisms that modulate the cell metabolic activities and biosynthesis. Attempts have been made to model the chondrocytes embedded in the collagen-proteoglycan extracellular matrix to determine the distribution of local stress-strain field, fluid pressure and the time-dependent deformation of the cell. To date, these models still have not taken into account a remarkable characteristic of the cartilage extracellular matrix given rise from organization of the collagen fiber architecture, now known as the tension-compression nonlinearity (TCN)… More >

Jun Wang¹, Wei Huang², Raghbir S. Bhullar³, Pin Tong²

Molecular & Cellular Biomechanics, Vol.1, No.2, pp. 161-168, 2004, DOI:10.3970/mcb.2004.001.161

Abstract Surface-tension-driven blood flow into a capillary tube, as in some medical devices, is studied. In a previous article, we considered the early stages of the entry flow from a drop of blood into a capillary, and solved the problem analytically under the assumption that the resistance of the air is negligible. In the present note we consider a capillary tube of finite length, with the far end containing a small window which opens to the atmosphere. The dynamic reverberation of the air in the capillary tube is analyzed in conjunction with the dynamics of the… More >

Dan Givoli¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.6, pp. 497-514, 2004, DOI:10.3970/cmes.2004.005.497

Abstract Very thin layers with material properties which significantly differ from those of the surrounding medium appear in a variety of applications. Traditionally there are two extreme ways of handling such layers in finite element analysis: either they are fully modelled or they are totally ignored. The former option is often very expensive computationally, while the latter may lead to significant inaccuracies. Here a special technique of modeling thin layers is devised within the framework of the finite element method. This technique constitutes a prudent compromise between the two extremes mentioned above. The layer is replaced More >

Kunigal Shivakumar¹, Anil Bhargava²

CMC-Computers, Materials & Continua, Vol.1, No.2, pp. 173-190, 2004, DOI:10.3970/cmc.2004.001.173

Abstract The fiber optic sensor (FOS) embedded perpendicular to reinforcing fibers causes an `Eye' shaped defect. The length is about 16 times fiber optic radius (R_Fos) and height is about 2R_Fos. The eye contains fiber optics in the center surrounded by an elongated resin pocket. Embedding FOS causes geometric distortion of the reinforcing fiber over a height equal to 6 to 8 R_Fos. This defect causes severe stress concentration at the root of the resin pocket, the interface (in the composite) between the optical fiber and the composite, and at 90° to load direction in the composite. The… More >