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 >

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 >

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 >

Yan Wang¹, Weina Li¹, Jorg Weissmoller^2,3, 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 >

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 >

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 >

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 >

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 >

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 >

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 >