N. Shishido, T. Ikeda, N. Miyazaki

CMES-Computer Modeling in Engineering & Sciences, Vol.35, No.1, pp. 1-20, 2008, DOI:10.3970/cmes.2008.035.001

Abstract We propose an image correction method that will accurately measure full-field displacement in a microstructure using the digital image correlation method (DICM); the proposed method is suitable for use with laser-scanned images. Laser scanning microscopes have higher spatial resolution and deeper depth of field than optical microscopes, but errors in laser scanning position (time-dependent distortion) affect the accuracy of the DICM. The proposed image correction method involves the removal of both time-dependant and time-independent distortions. Experimental results using images of prescribed rigid-body motions demonstrate that the proposed correction method is capable of identifying and removing… More >

H.K. Mebatsion^1,2, P. Verboven¹, P. T. Jancsók¹, Q.T. Ho¹, B.E. Verlinden³, B.M. Nicolaï^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.29, No.3, pp. 137-150, 2008, DOI:10.3970/cmes.2008.029.137

Abstract Transport processes of gas and moisture are among the most important physiological processes in plant tissue. Microscale transport models based on Navier-Stokes equations provide insight into such processes at the microscopic scale. Due to microscopic complexity, numerical solutions based on the finite element or finite volume methods are mandatory. Therefore, a 3D geometric model of the tissue is essential. In this article, a novel algorithm for geometric reconstruction of 2D slices of synchrotron tomographic images is presented. The boundaries of 2D cells on individual slices were digitized to establish a set of boundary coordinates and… More >

B. Yang^1,2, S.-C. Wong³, S. Qu³

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 81-94, 2008, DOI:10.3970/cmes.2008.024.081

Abstract In the modeling of overall property of composites, the effect of particle interaction has been either numerically taken into account within a (representative) volume element of a small number of particles or neglected/ignored in order for efficient solution to a large system of particles. In this study, we apply the point-defect Green's function (GF) to take into account the effect of particle interaction. It is applicable to small volume fractions of particles (within 10 %). The high efficiency of the method enables a simulation of a large system of particles with generally elastic anisotropy, arbitrary… More >

H. Payer¹, T. Haschke¹, R. Reichardt¹, G. Li², K. Graf^2,3, W. Wiechert^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 61-76, 2008, DOI:10.3970/fdmp.2008.004.061

Abstract Microstructured surfaces are of steadily increasing importance in a large variety of technological applications. For the purpose of quality assurance, e.g. during variation studies of experimental parameters or for comparison with results from simulations, the surface geometry must be precisely measured and described in terms of geometric parameters. An analysis tool for regularly structured surfaces is presented that performs a highly automated evaluation of surface scanning data and derives geometric quality control parameters. To demonstrate the power of the analysis tool it is exemplarily applied for the investigation of microcraters emerging after the evaporation of… More >

J. Toribio ¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 239-248, 2006, DOI:10.3970/sdhm.2006.002.239

Abstract This paper reviews the fracture performance in air and aggressive environment (stress corrosion cracking) of eutectoid prestressing steel wires with different levels of cold drawing. In air environment, a micromechanical model of fracture is proposed to rationalize the results on the basis of the microstructure of the steels after drawing and the model of Miller & Smith of fracture of pearlitic microstructure by shear cracking of the cementite lamellae. In hydrogen assisted cracking (HAC), a microstructure-based model is proposed on the basis of the Miller & Smith model and the mechanism of hydrogen enhanced decohesion or, more More >

H.K. Mebatsion¹, P. Verboven¹, Q. T. Ho¹, F. Mendoza¹, B. E. Verlinden², T. A. Nguyen¹, B. M. Nicolaï^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.1, pp. 1-14, 2006, DOI:10.3970/cmes.2006.014.001

Abstract Modeling plant microstructure is of great interest to food engineers to study and explain material properties related to mass transfer and mechanical deformation. In this paper, a novel ellipse tessellation algorithm to generate a 2D geometrical model of apple tissue is presented. Ellipses were used to quantify the orientation and aspect ratio of cells on a microscopic image. The cell areas and centroids of each cell were also determined by means of a numerical procedure. These characteristic quantities were then described by means of probability density functions. The model tissue geometry was generated from the… More >

K. Yashiro¹, Y. Nakashima¹, Y. Tomita¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.2, pp. 73-80, 2006, DOI:10.3970/cmes.2006.011.073

Abstract A simple back force model is proposed for a dislocation cutting into γ' precipitate, taking the work formaking and recovering an anti-phase boundary (APB) into account. The first dislocation, or a leading partial of a superdislocation, is acted upon by a back force whose magnitude is equal to the APB energy. The second dislocation, or a trailing partial of a superdislocation, is attracted by the APB with a force of the same magnitude. The model is encoded in the 3D discrete dislocation dynamics (DDD) code and applied to the cutting behavior of dislocations at a… More >

Dongsheng Li^1,2, Ghazal Saheli¹, Moe Khaleel², Hamid Garmestani¹

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 31-42, 2006, DOI:10.3970/cmc.2006.004.031

Abstract A multiscale model based on statistical continuum mechanics is proposed to predict the mechanical and electrical properties of heterogeneous porous media. This model is applied within the framework of microstructure sensitive design (MSD) to guide the design of the microstructure in porous lanthanum strontium manganite (LSM) fuel cell electrode. To satisfy the property requirement and compatibility, porosity and its distribution can be adjusted under the guidance of MSD to achieve optimized microstructure. More >

D. Ballhause¹, M. König¹, B. Kröplin¹

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 21-30, 2006, DOI:10.3970/cmc.2006.004.021

Abstract The mechanical behaviour of woven fabrics is dominated by the kinematics of the constituents on the microscopic scale. Their macroscopic response usually shows non-linearities which are due to the mobility of the interlaced yarns. The major deformation mechanisms of fabrics, i.e. the crimp interchange in case of biaxial tension and the trellising motion of the yarns in case of shear, reflect the dependency of the macroscopic material behaviour on the microstructural deformation mechanisms.
We present a novel modelling approach for woven fabrics which is capable to represent directly and locally the microstructure and its kinematics… 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 >