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Yang Cheng, Bin Jia, Ming Xin
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 33-34, 2011, DOI:10.3970/icces.2011.016.033
Abstract A sparse grid approach to orbit uncertainty propagation is presented. Efficient and accurate uncertainty propagation methods for nonlinear dynamic systems have been of enormous interest to space object tracking. Recent methods include those based on the time evolution of the probability density function, the statistical moments, the random samples, or a sum of Gaussian components. The idea of the sparse grid method for orbit uncertainty propagation is to represent the initial uncertainty by a sparse grid, propagate the sparse grid points individually through the nonlinear orbit dynamics, and compute the statistical moments from the propagated sparse grid points. The Smolyak… More >

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Haofeng Chen
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 35-36, 2011, DOI:10.3970/icces.2011.016.035
Abstract In this paper a state-of-the-art numerical method is discussed for the evaluation of the shakedown and ratchet limits for an elastic-perfectly plastic body subjected to cyclic thermal and mechanical load history. The limit load, i.e. the load carrying capacity, is also determined as a special case of shakedown analysis. These design limits in plasticity have been solved by characterising the steady cyclic state using a general cyclic minimum theorem. For a prescribed class of kinematically admissible inelastic strain rate histories, the minimum of the functional for these design limits are found by a programming method, the Linear Matching Method (LMM),… More >

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608

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Xiaoyang LU, Bingtao TANG
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 37-38, 2011, DOI:10.3970/icces.2011.016.037
Abstract Bending movements will be caused when elements passing by die entrance radius. The classical inverse analysis method (CIAM) uses the constitutive equation based on deformation theory of plasticity. Based on the assumption of the proportional loading, Hencky deformation theory is adopted. The secant modulus is obtained from uniaxial tensile curve and the plastic strain rate can be directly integrated to obtain a total plastic strain expression. The CIAM of sheet metal stamping has the shortcomings of no consideration of the effects of deformation history on stress prediction. Therefore, there is some discrepancy between the stress calculated with CIAM and that… More >

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Myung Jo Jhung, Yong Ho Ryu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.016.039
Abstract Korea is developing one of advanced small and medium-sized reactor called SMART (System-integrated Modular Advanced ReacTor), an integral type pressurized water reactor with the thermal power of 330 MW, by combining innovative safety features and its own indigenous technologies with proven light water reactor technologies. The reactor assembly of SMART contains major primary systems such as fuel and core, 8 steam generators, a pressurizer, 4 main coolant pumps, and 25 control rod drive mechanisms in a single pressurized reactor vessel. The integrated arrangement of these components enables the removal of the large size pipe connections between major components of reactor… More >

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637

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Sukumar Srikant, Maruthi Akella
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 41-42, 2011, DOI:10.3970/icces.2011.016.041
Abstract We investigate state observer design for systems endowed with shared-sensing and control through reversible transducers. In this framework, reversible transducers are continually switched between the actuation and sensing modes at some specified schedule. Design and analysis of stable state-observers and feedback controllers for these classes of switched/hybrid systems are significantly complicated by the fact that at any given instant of time, the overall system loses either controllability (during the sensing phase) or observability (during the actuation phase). In this work, we consider linear systems with a single shared-sensing (reversible) transducer and provide a novel observer that guarantees exponential reconstruction of… More >

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Yan-Bin Jia
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 43-44, 2011, DOI:10.3970/icces.2011.016.043
Abstract The robot hand applying force on a deformable object will result in a changing wrench space due to the varying shape and normal of the contact area. Design and analysis of a manipulation strategy thus depend on reliable modeling of the object's deformations as actions are performed. The first part of this talk is concerned with modeling of shell-like objects grasped by a robot hand. We present a formulation of extensional, shearing, and bending strains in terms of geometric invariants including the principal curvatures and vectors, and their related directional and covariant derivatives. A computational procedure is then offered for… More >

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650

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Lu Xiaoyang, Zhang Hao, Lu Xiaoli
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 45-46, 2011, DOI:10.3970/icces.2011.016.045
Abstract The elbow pipe is the crucial component of the piping system in many engineering fields such as metallurgical industry, material industry, petrochemical industry and chemical industry. Under high temperature and pressure (bulky flux, high velocity of flow) conditions, the non-uniformity of pressure loads has intensified the stress concentration in elbow pipe position. Meanwhile, it occurs obviously in destruction and expiration due to the disfigurement of manufactural technics and partial intensity insufficient. Therefore, the analysis of flow characteristics for elbow and the calculation formula of pressure in elbow are of important theoretical significance and applied value.

After an analytical overview… More >

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Tomasz Kubiak, Mariusz Urbaniak
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 47-48, 2011, DOI:10.3970/icces.2011.016.047
Abstract The paper deals with static and dynamic buckling of thin-walled C-shape girders subjected to compression or/and bending pulse loading with different pulse shape. The rectangular, trapezoidal and triangular shape of pulse have been considered. The employed pulse duration is comparable with period of natural vibration.

The unidirectional fibre composite material was modelled as orthotropic one. The material properties was designed using theory of mixture. The dynamic behaviour of such structures subjected to bending or/and compression have been under analysis. To investigate the local dynamic buckling only one segment of girders was taken into consideration.

For finding the critical… More >

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ZHANG Hong-tao¹, ZHAO Yu-fei², Wang Xiao-chun¹, Liu Ying-hua³
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 49-50, 2011, DOI:10.3970/icces.2011.016.049
Abstract This paper is to study the stability of jointed rock slope using the Goodman joint element and upper bound limit analysis. Assumed the constitutes of rock masses, rock block and joint, obey perfect rigid plasticity and Mohr-Coulomb yield criterion, an upper bound finite element formulation is build to study the stability analysis of jointed rock slope using the Goodman joint element. A nonlinear mathematical programming is formulated with equation constraints and the loading factor of external load or self-weight as the objective function, and a direct iterative algorithm is constructed to solve it. Numerical results are given to illustrate the… More >

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Zhenhan Yao, Yintao Wei
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 51-52, 2011, DOI:10.3970/icces.2011.016.051
Abstract Shape optimization is very important in many engineering fields. As conventional engineering design, the shape optimization is generally based on the finite element analysis. Because many engineering strutures are related to different nonlinear problems in their working state, the analysis for each design sample is quite time consuming. For example for the shape optimization of automotive tires, it is related to the geometrical, material nonlinearity, and boundary nonlinearity caused by the contact problem. Therefore, the finite element analysis combined with sensitivity analysis to get more information for each design sample is a strategy usually adopted. For the sensitivity analysis, the… More >

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Chein-Shan Liu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 53-54, 2011, DOI:10.3970/icces.2011.016.053
Abstract We consider an inverse problem for identifying a time-space-dependent heat transfer coefficient h(x,t) in a two-dimensional heat conduction equation, with the aid of an extra measurement of temperature at the top side of a rectangular plate. Finite differences are used to discretize the governing equation and boundary conditions of Neumann type, and then the Fictitious Time Integration Method (FTIM) is used to solve a large scale linear system of unknown variables. The numerical results show that the FTIM is effective and robust against noise. More >

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Kowal-Michalska K., Mania R.J.
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 55-56, 2011, DOI:10.3970/icces.2011.016.055
Abstract The static and dynamic buckling analysis is conducted for functionally graded composite plates under edgewise compression. The rectangular FGM plates with simply supported edges are studied. In the applied model the material properties vary continuously in the thickness direction according to a simple power law distribution in terms of constituents - it is the ceramic and metal volume fractions. The analyzed plate is composed of ceramic (zirconia or TiC) and metal (steel or aluminum, respectively) phases. Different through-thickness mechanical material properties have been modeled by the volume fraction exponent of value in the range of 0.1A.10. The mechanical material properties… More >

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638

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Alamusi, Yaolu Liu, Ning Hu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 57-58, 2011, DOI:10.3970/icces.2011.016.057
Abstract In this work, we propose a 3 dimensional (3D) numerical model to predict the piezoresistivity behaviours of a nanocomposite material made from an insulating polymer filled by carbon nanotubes (CNTs). This material is very hopeful for its application in highly sensitive strain sensor by measuring its piezoresistivity, i.e., the ratio of resistance change versus applied strain. In this numerical approach, a 3D resistor network model is firstly proposed to predict the electrical conductivity of the nanocomposite with a large amount of randomly dispersed CNTs under the zero strain state. By focusing on the fact that the piezoresistivity of the nanocomposite… More >

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Y. Zhao, K.S. Yeo, P. Yu, S.J. Ang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 59-60, 2011, DOI:10.3970/icces.2011.016.059
Abstract This paper presents the application of an Arbitrary Lagrangian Eulerian (ALE) and Singular Value Decomposition (SVD) based Generalized Finite Difference (GFD) method to simulate the C- and S-starts of a carangiform-type fish. The numerical model incorporate fluid-structure interaction (FSI) and computation is carried out on a hybrid grid comprising meshfree nodes around the undulating/deforming swimming fish and Cartesian nodes in the background. The meshfree nodes convect with the deformation and motion of the swimmer. A curvature-wave model of the backbone is used to generate the C- and S-start actions of the fish from the experimental data of Spierts and Leeuwen… More >

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735

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Yeong-Ley Tsay^*, Jen-Chieh Cheng, Zhi-Hang Zhan
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 61-62, 2011, DOI:10.3970/icces.2011.016.061
Abstract A lot of researchers have dealt with the heat transfer enhancement of block heat sources mounted on the channel walls by using baffle. On the other hand, the heat generating components are allocated inside the channel or cabinet in many engineering applications. This study aims firstly to investigate the characteristics of conjugate heat transfer of conduction-forced convection in a rectangular channel containing a block heat source module. The module is comprised of a board and five block heat sources mounted discretely on the up surface of the board. Furthermore, efforts are carried out to explore the enhancement of cooling performance… More >

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683

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ZHIBIN LU, YUANLI XU, HANG SHAO, JIANGONG LI
The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 63-64, 2011, DOI:10.3970/icces.2011.016.063
Abstract This paper reports the effects of strain rate and temperature on the steady state flow stress of metallic glasses. Based on the energy conservation between the applied mechanical work and the increased energy in metallic glasses at steady state flow, the steady state stress of metallic glasses was found to depend on difference in free volume between undeformed state and steady state of flow. The effects of strain rate (or temperature) on the steady state flow stress can be described by a linear relationship between the steady state flow stress and temperature (or logarithm of strain rate). More >

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