Home / Journals / ICCES / Vol.18, No.4, 2011
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  • Open AccessOpen Access

    ABSTRACT

    A Spatial FEM Model of Thermal and Mechanical Action in RCC dam

    M. S. Jaafar, J. Noorzaei, A. A. Abdulrazeg, T. A. Mohammed, P.Khanehzaei
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 97-98, 2011, DOI:10.3970/icces.2011.018.097
    Abstract Specific features of the thermal stress fields in roller compacted concrete (RCC) dam are always their spatial character and completely dependent on the maturity functions such as deformations properties (elastic, creep). The thermal changes in the material affect the elastic, creep properties of the material, and in turn, the stress fields within the structure. Therefore, the effects of temperature on the properties of RCC materials( elastic, creep) has to be taken into account in order to determine the risk of the thermally induced cracking in these dams. In this study, a viscoelastic model, including ageing effects and thermal dependent properties… More >

  • Open AccessOpen Access

    ABSTRACT

    Optimization of the Multiple-Relaxation-Time Micro-Flow Lattice Boltzmann Method

    K. Suga, T. Ito
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 99-100, 2011, DOI:10.3970/icces.2011.018.099
    Abstract Evaluation and optimization of the multiple-relaxation-time (MRT) lattice Boltzmann method for micro-flows (micro-flow LBM) are performed with the two-dimensional nine discrete velocity (D2Q9) model. The MRT micro-flow LBM consisting of the combination of bounce-back and full diffusive (CBBFD) wall boundary condition is considered. Based on the discussion of Chai et al. (2010), the presently applied CBBFD model and relaxation time for heat flux satisfy the second-order slip boundary condition. However, modification to the MRT model of Chai et al. (MRT-C) is made to the relaxation time for the moments related to the stress by introducing the psi function (Stops,1970; Guo… More >

  • Open AccessOpen Access

    ABSTRACT

    Wavelet BEM for large-scale Stokes flow simulation

    Jinyou Xiao, Wenjing Ye
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 101-102, 2011, DOI:10.3970/icces.2011.018.101
    Abstract Traditional boundary element methods (BEMs) suffer from densely populated system matrices. In recent years, acceleration techniques like the wavelet BEM (WBEM) have been developed which reduce the complexity considerably. In WBEM, one uses appropriate wavelet bases for the discretization, yielding numerically sparse matrices which result in extremely fast matrix-vector multiplications. However, in conventional WBEM the wavelets are constructed by uniform refinement of parametrically described patches. Such approaches have difficulties in dealing with practical problems with complicated geometries because patch-wise surface parameterization is generally not available. To avoid this limitation, Tausch proposed a method in [1] to construct wavelets directly on… More >

  • Open AccessOpen Access

    ABSTRACT

    Calcium Response and Transfer in Bone Cell Network with or without Gap Junctions under Mechanical Stimulation

    Bo Huo, Man Hu, Ping Li
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 103-104, 2011, DOI:10.3970/icces.2011.018.103
    Abstract It has been widely accepted that movement of human body causes the fluid flow through pores or channels inside bone and subsequently on osteoblasts on the surface of trabeculae and osteocytes inside lacunae. The mechanism of calcium response in a bone cell and calcium transfer between bone cells is critical in understanding the communication between bone cells and calcium deposition on bone matrix. Our previous works have demonstrated that when micropatterned osteoblastic cell network with gap junctions was exposed to fluid flow, extracellular ATP diffusion following the activation of calcium response in neighboring cells plays more important roles in calcium… More >

  • Open AccessOpen Access

    ABSTRACT

    Advancing Surface Metrology Capabilities with Specialized White Light Interferometry

    Dong Chen
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 105-106, 2011, DOI:10.3970/icces.2011.018.105
    Abstract Optical profilers have been widely used in many areas of surface measurements and characterizations, measuring parameters such as surface roughness, transparent films and coating thickness, nano- and micro-size structures, form and shape of mechanical parts, flatness of wafer and so on. In this presentation, we will discuss a spectrum of 3D measurement techniques using optical profiler and its applications in R&D lab and industrial production lines. The developments of the techniques are mostly application oriented. They target some measurement challenges encountered in optical 3D metrology applications. These techniques include both software algorithm developments and hardware improvements. The issues addressed in… More >

  • Open AccessOpen Access

    ABSTRACT

    FLOW CONTROL RESEARCH AT NASA GLENN FOR GAS TURBINE ENGINES

    D. R. Reddy1
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 107-112, 2011, DOI:10.3970/icces.2011.018.107
    Abstract Flow control is used on aerodynamic surfaces to improve flow quality by reducing or eliminating undesirable flow features such as thick boundary layers and possible flow separation that lead to large energy losses resulting in negative impact on performance of the flow device. As the demand for more efficient gas turbine engines increases in the future, flow control technology in various components of the engine will be critical in enabling the future designs to meet the necessary performance requirements.

    Technology advancement in gas turbine engines used for aerospace propulsion has been focused on achieving significant improvement in thrust-to-weight ratio… More >

  • Open AccessOpen Access

    ABSTRACT

    Water Mediated Non-Selective Conduction of K+ and Na+ in NaK Channel

    Rong Shen, Guangchao Zuo, Wanlin Guo
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 113-114, 2011, DOI:10.3970/icces.2011.018.113
    Abstract The NaK channel from Bacillus cereus, with properties of Na+ and K+ permeability and Ca2+ blockage, is the first structure of cation channels without high selectivity to K+ ion. Here, we investigate the mechanism for non-selective ion conduction in NaK channel by systematical molecular dynamics simulations. It is shown that K+ ions prefer to bind within the sites formed by two adjacent planes of oxygen atoms from the selectivity filter, while Na+ ions are inclined to bind to a single plane of four oxygen atoms. Meanwhile, we find four small grottos connecting with the vestibule of the NaK selectivity filter,… More >

  • Open AccessOpen Access

    ABSTRACT

    Application of the Gradient Smoothing Technique to the Natural Neighbour Galerkin Method for the Couple-Stress Elasticity

    K. Wang, S.J. Zhou, Z.F. Nie
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.018.115
    Abstract The natural neighbour Galerkin method is tailored to solve boundary value problems of the couple-stress elasticity to model the size dependent behaviour of materials. This method is based on the displacement-based Galerkin approach, and the calculation of the global stiffness matrix is performed using gradient smoothing technique combined with the non-Sibsonian partition of unity approximation scheme. This method possesses the following properties: the complex C1-continuous approximation scheme is avoided without using either Lagrange multipliers or penalty parameters; no domain integrals involved in the assembly of the global stiffness matrix; and the imposition of essential boundary conditions is straightforward. The validity… More >

  • Open AccessOpen Access

    ABSTRACT

    Mechanics of complex surfaces by multi-scale modeling

    Yan Wang1, Weina Li1, Jorg Weissmoller2,3, Huiling Duan1
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 117-118, 2011, DOI:10.3970/icces.2011.018.117
    Abstract Surface stress plays a very important role in surface morphology evolution [1-3]. Since the bonding configurations of the atoms at surfaces become different when adsorbates are situated on the surfaces, surface stress can be altered by the presence of adsorbates. Moreover, unless experiments are carried out on high quality single crystals, the surface will typically exhibit corrugation or roughness even when it is nominally planar. We have analyzed this kind of problem and pointed out that stress can be quite significantly affected by surface roughness when the microstructure scale reaches the nanometer range [4].

    Therefore, we first build a… More >

  • Open AccessOpen Access

    ABSTRACT

    Investigation on Material Properties by Synchrotron Radiation X-Ray Computed Tomography

    Hu Xiaofang, Xu Feng, Wang Ming, Wu Xiaoping
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 119-120, 2011, DOI:10.3970/icces.2011.018.119
    Abstract The Synchrotron Radiation X-ray Computed Tomography (SR-CT) technique is a non- destructive detection technology which can give the in-situ observation of microstructure evolution of materials under the external field (e.g., high pressure, high temperature, electromagnetic field, intense radiation, etc.), and it has a significant application in the area of plants and crops, advanced manufacturing, advanced materials, biomedicine, mechanics, archaeology and so on. More >

  • Open AccessOpen Access

    ABSTRACT

    Effects of Tangent Operators on Prediction Accuracy of Meso-mechanical Constitutive Model of Elasto-plastic Composites

    Sujuan Guo, Guozheng Kang, Juan Zhang
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 121-122, 2011, DOI:10.3970/icces.2011.018.121
    Abstract With a newly developed homogenization cyclic constitutive model of particle reinforced metal matrix composites (Guo et al., 2011), the effects of tangent operators, i.e., continuum and algorithmic tangent operators [defined by Doghri and Ouaar (2003)] on the accuracy of the developed meso-mechanical constitutive model to predict the monotonic tensile and uniaxial ratchetting deformation of SiCP/6061Al composites were investigated in this work. The predicted results were obtained by the developed model with the choices of different tangent operators and various magnitudes of loading increments. Some useful accuracy comparison and error analysis on the predicted results were conducted. It is shown that:… More >

  • Open AccessOpen Access

    ABSTRACT

    Mechanical models for human tracheas based on uniaxial extension test

    xuan pei
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 123-124, 2011, DOI:10.3970/icces.2011.018.123
    Abstract The constitutive model always plays a fundamental role in biomechanical researches on human trachea soft tissues. Due to the variety of constitutive theories, the selection of the appropriate one and the determination of its material parameters becomes a question. Based on longitudinal and circumferential extension tests on human tracheas, three constitutive models-the isotropic M-R model, the Holzapfel's anisotropic model and modified Hozapfel's model respectively, were utilized in this paper to fit the experimental data. A jointly fitting strategy was also proposed to obtain the anisotropic model parameters. For the isotropic M-R model, material parameters optimized from different directions are significantly… More >

  • Open AccessOpen Access

    ABSTRACT

    Surface Piezoelectricity and Surface Wave Propagation in a Piezoelectric Half-space with Surface Effect

    Weiqiu CHEN
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.018.125
    Abstract We will report a theory of surface piezoelectricity which governs a plane surface of a piezoelectric body. The piezoelectric surface may be endowed with different properties from the bulk material, and can account for the well-known surface effect which becomes increasingly important in micro- or nano-sized structures. In this study, the surface is treated as a piezoelectric thin layer of thickness h, and the state-space formulism is adopted to obtain the transfer relation between the state vectors at the top and bottom surfaces of the layer. The power series of the transfer matrix is then used, which can be truncated… More >

  • Open AccessOpen Access

    ABSTRACT

    Multi-Physics Simulation by Quantum Chemical Molecular Dynamics

    Momoji Kubo
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 127-128, 2011, DOI:10.3970/icces.2011.018.127
    Abstract The establishment of the process and material design technology based on theoretical science at electronic- and atomic-level is one of the important subjects in order to solve the energy and environmental problems, to realize the safe and secure society, and to create new industry and markets. Especially, the recent material, process, and system technologies constitute of multi-physics phenomena including chemical reaction, friction, impact, stress, fluid, photon, electron, heat, electric and magnetic fields etc., and then the deep understanding of the above multi-physics phenomena are essential. Previously, continuum simulations such as finite element method have been employed for the investigation on… More >

  • Open AccessOpen Access

    ABSTRACT

    Large deflection analysis for thin-plate bending problem using HRK approximation

    Shota Sadamoto, Satoyuki Tanaka, Shigenobu Okazawa
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 129-130, 2011, DOI:10.3970/icces.2011.018.129
    Abstract In this presentation, large deflection analysis for thin-plate bending problem using Hermite Reproducing Kernel (HRK) approximation is presented. HRK approximation for thin-plate bending problem is one of meshfree/particle approaches and is proposed by Wang [1]. The deflection and rotations are represented by the Hermite-type approximation. In the formulation, the rotations are represented by the differentiation of deflection and the approximation is satisfied Kirchhoff Mode Reproducing Condition (KMRC). Sub-domain stabilized nodal conforming integration is adopted to enforce integration constraint in the numerical integration. Total Lagrangian method is adopted to solve thin-plate bending problem with geometrical non-linearity. Green-Lagrange strain and second Piola… More >

  • Open AccessOpen Access

    ABSTRACT

    Lattice Boltzmann Simulation of Dynamic Behavior of Liquid Droplets on Solid Surfaces

    Masato Yoshino, Yoshito Tanaka, Keisuke Yano
    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 131-132, 2011, DOI:10.3970/icces.2011.018.131
    Abstract Dynamics of droplet impact on solid surfaces is of great importance in many engineering applications such as ink-jet printing and rapid spray cooling of hot surfaces. In this study, the lattice kinetic scheme based on the lattice Boltzmann method for immiscible two-phase fluids [Inamuro (2006)] is applied to such micro-fluid problems. The present method enables us to perform stable calculations of two-phase flows with large density ratios of up to 1000. The boundary condition based on the wetting potential that is calculated according to a prescribed static contact angle is used on solid surfaces [Briant, Papatzacos, and Yeomans (2002)]. First,… More >

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