M. Toujani¹, R. Djebali², L. Hassini¹, S. Azzouz¹, A. Belghith¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.5, pp. 469-485, 2014, DOI:10.3970/cmes.2014.098.469

Abstract In the present work we aim to simulate unsteady two-dimensional evolution of the moisture content, temperature and mechanical stress in a parallelepiped apple sample during convective drying. The model is based on the heat and mass transfer equations and the mechanical equilibrium equation under the assumptions of plane deformation, viscoelasticity and isotropic hydric shrinkage. The Finite Elements COMSOL Multiphysics solver is used to solve the developed model. The hydro-thermal model was validated on experimental data drawn in our laboratory for moisture and temperature internal profiles of the product. Excellent agreement has been obtained between numerical and measured data for different… More >

V.B.Shim ¹, K. Mithraratne ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 279-294, 2014, DOI:10.32604/cmes.2014.098.279

Abstract The activation of NF-kB is an important precursor in developing melanoma. However the role of mechanical stimulation in the NF-kB activation has not been studied. We used a multiscale computational modeling approach to investigate the role of mechanical stimulation and the skin tissue internal structures in the activation of NF-kB. Our model is made up of three levels – 1) the macro level where a FE model of the Zygomaticus major muscle was developed; 2) the meso level where a micro FE model of the skin block using a sample from human cadaver was developed; 3) the cell level where… More >

Zhengzheng Cao¹, Yuejin Zhou^1,2, Ping Xu¹, Jiawei Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.5, pp. 351-364, 2014, DOI:10.3970/cmes.2014.101.351

Abstract In accordance with the influence of underground mining on the deformation and failure of a shallow-buried gas pipeline, the pipe-soil interaction during mining is classified into two stages, namely coordinated deformation stage and partial hanging stage. According to the mechanical characteristics of the buried pipeline in each stage, the models of a) a beam on an elastic foundation, b) an elastic beam under uniform load, and c) a vertical and horizontal bending beam are introduced in a mining subsidence zone to mechanically analyze, respectively a) the pipeline in non-mining subsidence zone, b) the pipeline at the coordinated deformation stage, and… More >

Deli Gao^1,2, Lianzhong Sun^1,3, Hongshu Wei⁴, Shunwen Wang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.2, pp. 143-162, 2012, DOI:10.3970/cmes.2012.089.143

Abstract Due to the complexity of forces acting on the down-hole tubular strings in extended reach drilling (ERD), the factors which influence the process should be taken into account as much as possible, in order to predict the down-hole drag & torque more accurately. This can help us to identify and prevent the problems related to downhole drag & torque in ERD. The effects of such factors, as the tubular buckling, the buoyancy, the mechanical resistance and the friction reducer, on down-hole drag & torque, are taken into account in this paper, in order to improve the accuracy of the prediction… More >

Fei Yin¹, Deli Gao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.1, pp. 25-38, 2012, DOI:10.3970/cmes.2012.089.025

Abstract The methods to design the casings used in oilfields, are currently based on the assumptions that the remote crustal-stress-field is axially symmetric, in plane strain. However, most of the failures of the casings are caused by non-uniform and asymmetric far-field crustal stresses, so that it is necessary for a proper design of the casings, to investigate and understand the casing's behavior under non-uniform far-field crustal stresses. A mechanical model is first established for the system, consisting of the casing and formation, by using the plane strain theory of linear elasticity. The non-uniform crustal stress is resolved into a uniform stress… More >

MC. Ho Ba Tho¹, PE Mazeran², K El Kirat¹, S.F. Bensamoun¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 557-578, 2012, DOI:10.3970/cmes.2012.087.557

Abstract Mechanical properties of cortical human bone have been investigated for more than four decades. Numerous experimental investigations on bone characterization were performed ; mechanical, vibrational, acoustical testing and morphological, physico-chemical investigations. Due to the techniques, different levels of investigation were performed and subsequently quantitative parameters are concerning different level of structure of bone (organ, tissue,... ). According to our knowledge, few investigations were performed simultaneously on mechanical, morphological and physico-chemical properties of bone. The objectives of the present study were to investigate the influence of multiscale structural characteristics of the bone tissue on its mechanical behavior and to provide some… More >

R. Khanna^1,2, D. R. Katti¹, K. S. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 530-556, 2012, DOI:10.3970/cmes.2012.087.530

Abstract Here we report a new in situ nanoindentation technique developed to evaluate the composite mechanical behavior of cell-biomaterial construct under physiological conditions over the time scale of bone nodule generation. Using this technique, mechanical behavior of osteoblast cell-substrate interfaces on tissue engineered materials (chitosan-polygalacturonic acid-nanohydroxyapatite (CPH) films) is investigated. Mechanical behavior of cells in the elastic regime over the time scale of cell adhesion (1 day), proliferation (4 days), development (8 days) and maturation (22 days) of bone nodules is evaluated. Our results indicate that the elastic properties of flat cells are higher (indicating stiffer response, after 4 days, as… More >

J.A. García^1,2, J.M. Peña¹, S. McHugh², A. Jérusalem^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.5, pp. 411-432, 2012, DOI:10.3970/cmes.2012.087.411

Abstract Neuronal growth is a complex process involving many intra- and extracellular mechanisms which are collaborating conjointly to participate to the development of the nervous system. More particularly, the early neocortical development involves the creation of a multilayered structure constituted by neuronal growth (driven by axonal or dendritic guidance cues) as well as cell migration. The underlying mechanisms of such structural lamination not only implies important biochemical changes at the intracellular level through axonal microtubule (de)polymerization and growth cone advance, but also through the directly dependent stress/stretch coupling mechanisms driving them. Efforts have recently focused on modeling approaches aimed at accounting… More >

Yun Chen¹, Junzhi Cui², Yufeng Nie¹, Yiqiang Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.76, No.3&4, pp. 189-206, 2011, DOI:10.3970/cmes.2011.076.189

Abstract This paper presents a new numerical algorithm for thermal-mechanical coupled analysis of polycrystalline aggregates based on the plastic slip theory inside crystals and the frictional contact on their interfaces. It involves the mechanics and heat conduction behaviors caused by both force loads and temperature changing within crystal and contact interfaces between crystals. Firstly, the constitutive relationship inside single crystal, and the moment equations and energy equations are derived by means of rate-dependent plastic deformation theory and the formulation of elastic-plastic tangent modulus depended on temperature. Secondly, the contact conditions with friction, including frictional heat generation and heat transfer across the… More >

Francesca Cosmi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.3&4, pp. 269-282, 2011, DOI:10.3970/cmes.2011.074.269

Abstract In industrial applications, microstructure inhomogeneities can derive from the manufacturing process and the final mechanical properties of the material depend on the resulting, complex, structural pattern of the constituents. In this paper, Cell Method plane models in the elastic and plastic fields are presented and applied to predict the behaviour of four sintered alloys, where the spatial arrangement of voids within the base material contributes to determine the mechanical behaviour. Unlike the Finite Elements and other methods, the Cell Method is a numerical method based on a direct discrete formulation of equilibrium equations, so that no differential formulation is needed… More >