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C.T. Kwan, C.C. Wang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 1-2, 2011, DOI:10.3970/icces.2011.018.001
Abstract In this paper, a pre-stress die design method for cold backward extrusion with a non simple hollow cylinder die by using response surface method is proposed. The radius of the interface and the absolute interference in the interface of a prestress die are chosen as the design variables. Both the two design variables are set at four levels, and then 16 combinations of design parameters are constituted totally. A finite element based code is utilized to investigate the elastic deformation characteristic under different design parameters, and the response surface method is then employed to synthesize the data sets obtained from… More >

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722

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L. J. Qin¹, X.F. Li¹, X.G. Yang², Z.W. Zhang², Z. H. Feng², H. Miao¹, Y. Wang¹, L.H. He¹, X.L. Gong^1,*
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 3-4, 2011, DOI:10.3970/icces.2011.018.003
Abstract Three-dimensional (3D) woven carbon/carbon (C/C) composites have attracted considerable attention in recent years. In comparison to the laminated composites, the carbon composites show better merit due to their strong through-the-thickness properties, high damage tolerance, and dimensional stability. However, the deformation of these materials is usually non-uniform. The strain field distribution is highly dependent on the heterogeneity of 3D woven structure. Therefore, the traditional techniques such as strain gauge are not suitable for measuring the deformation.

In this presentation, a full-field digital image correlation (DIC) technique was developed. The Iosipescu shear test (v-notched beam test) was employed to load the… More >

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677

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Yansheng He, Qingchuan Zhang, Shihua Fu, Qi Hu
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 5-6, 2011, DOI:10.3970/icces.2011.018.005
Abstract Abstract: The interaction of dislocation and solute atoms has great influence on the macroscopic mechanical behavior in alloys as well as the deformation of alloys. A dynamic Monte Carlo method is developed to simulate the interaction between dislocation and solute atom. The results show that dislocation motion is retarded by solute atoms in certain conditions. In the condition of constant external stress, the retarding effect of solute atoms becomes more inefficient with the increment of external stress. In the condition of constant stress rate, a step-like curve of the displacement-time indicates the intermittent motion of dislocation exhibiting dynamic strain aging… More >

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671

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Dein Shaw, Chih Ren Huang, Yi Chi Pan
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 7-8, 2011, DOI:10.3970/icces.2011.018.007
Abstract A nonlinear curved spring has a free form shape. In this study, the curved beam is applied a nonlinear load, the load on the spring is pointed to a certain point of the space. This curved spring can be used in an orthosis. A certain load-deformation relation of curved spring which used in orthosis can assist the subject wearing the orthosis to climb the stairs. The analysis of the curved spring should be non-linear due to the applied load is a constant but its direction is point to a certain point. The deformation is hard predicted correctly for this spring.… More >

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704

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Hongwei Guo
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 9-10, 2011, DOI:10.3970/icces.2011.018.009
Abstract It is an urgent need in engineering to measure the three-dimensional (3-D) shape of an object with specular surfaces by using optical techniques, despite some attempts for performing this task. This paper presents a moirAC-based technique for measuring the three-dimensional shapes of specular surfaces. In it, a Ronchi grating is closely located before the measured object and illuminated by a diffusive light source. When we observe the measured object through this grating, moirAC fringes are generated by the superposition of this grating and its virtual image produced by the measured specular surface. With this scheme, the movements of the grating… More >

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648

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Jia Fei, Xiu-Peng Zheng, Yan-Ping Cao^*, Xi-Qiao Feng
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.018.011
Abstract Recently, a novel technique based on the wrinkling of a bilayer composite film resting on a compliant substrate was proposed to measure the elastic moduli of thin films. In this paper, this technique is studied via theoretical analysis and finite element simulations. We find that under an applied compressive strain, the composite system may exhibit various buckling modes, depending upon the applied compressive strain, the geometric and material parameters of the system. We elucidate the physical mechanisms underlying the occurrence of two most typical buckling modes from the view point of energy. When the intermediate layer is much thicker than… More >

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P. Zhao, G. Shi
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 13-14, 2011, DOI:10.3970/icces.2011.018.013
Abstract The Poisson's ratios of a single layered graphene sheet and single-walled carbon nanotubes (SWCNTs) are computed using an improved equivalent structural mechanics model where the bond angle variations are modeled by the flexible connections of framed structures. The accuracy of the results given by the present model is evaluated by comparing the predicted results with the experimental data and the theoretical and computational results reported in the literature. It is shown that the Poisson's ratios given by the present computational model agree with the experimental data. The present result shows that the Poisson's ratios of both graphene and SWCNTs are… More >

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648

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Yuan Weifeng, Tan Kang Hai
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 15-16, 2011, DOI:10.3970/icces.2011.018.015
Abstract Generally, the computational efficiency in numerical analysis is dependant on the degree of freedom in the model under investigation. To reduce computational cost without altering the accuracy of numerical findings, an algorithm is introduced in this manuscript to develop macro element. When this method is incorporated into finite element analysis, all the members in the nonlinear zones of a structure can be grouped into just one macro element. With the presence of weak member method, the stiffness matrix of this macro element can be evaluated through analyzing the response of the original structure induced by a series of fictitious unit… More >

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662

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ZHANG Rong-gang^{1, 2,*}, ZHANG Hong-tao³, BAI Yu-xing³, GAO Jian-ling³, ZHANG Lai-yong², XU Bing-ye¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 17-18, 2011, DOI:10.3970/icces.2011.018.017
Abstract Based on the upper bound theorem, the fire resistance is studied using the combination of element collapse mechanisms of steel frames, where the element collapse mechanisms are automatically determined from independent mechanisms. The fire limit load is calculated by solving a nonlinear mathematical programming. The computing procedure is programmed by FORTRAN language. Results show that this method is useful to find the collapse mechanism with the lowest fire limit load, which can provide a theoretical and practical way for the fire design of steel frame structure. More >

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681

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Qian Kemao
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 19-20, 2011, DOI:10.3970/icces.2011.018.019
Abstract When a fringe pattern is obtained, it needs to be analyzed in order to extract the desired information. In this talk, we are going to introduce some fringe pattern analysis techniques that we proposed recently, such as windowed Fourier transform (WFT) [1], coherence enhancing diffusion (CED) [2], and frequency-guided sequential demodulation (FSD) [3]. Some results, along with discussions, are given for the following cases:
1. Filtering one fringe pattern
2. Phase retrieval from one closed fringe pattern
3. Phase retrieval from one carrier fringe pattern
4. Phase shift retrieval from two fringe patterns
5. Phase retrieval from a sequence of… More >

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755

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Gotthard Seifert, Aliezer Martinez Mesa, Sergei Yurchenko, Bassem Assfour¹, Thomas Heine³, Sergei Patchkovsk
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 21-22, 2011, DOI:10.3970/icces.2011.018.021
Abstract In this study structural characteristics of several carbon based nanostructures and organic frameworks as metal organic frameworks (MOF) and covalent organic frameworks (COF) on the hydrogen abundance in the material are investigated with the quantized liquid density functional theory (QLDFT), Molecular Dynamics (MD) and Grand Canonical Monte Carlo (GCMC). We applied these theories to evaluate the hydrogen storage capacities of nanoporous materials: Compact storage of hydrogen is the key challenge facing adoption of hydrogen as fuel for mobile applications. A promising approach to increase the storage densities is the adsorption of molecular hydrogen in porous environments. We have studied in… More >

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736

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Ching-Yuan Chang, Chien-Ching Ma
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 23-24, 2011, DOI:10.3970/icces.2011.018.023
Abstract Electronic speckle pattern interferometry (ESPI) is a full-field non-contact optical technique for displacement and vibration measurement. This study presents an anti-rigid-body motion (ARM) image processing method to improve the image quality of time-averaged ESPI method. The ARM method is based on the statistical optics and has the ability to reduce the perturbed rigid-body motion and background brightness influence. Finite element method (FEM) is applied to evaluate the resonant frequency and mode shape of piezoelectric ceramics, and compared with experimental measurements. In the resonant frequency comparison, ARM method presents 0.13% and 0.82% discrepancy in the third in-plane mode for U and… More >

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719

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Chen Minjiang, Fang Yu, Huanchao Yang, Haiqing Zhou, Lianfeng Sun
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 25-26, 2011, DOI:10.3970/icces.2011.018.025
Abstract Some of our recent experimental works on carbon nanotube and graphenes are presented in this work. There are mainly three parts, which are explained in more details as the followings:
1. Single-walled carbon nanotube crystal: a new condensed form of SWNTs-crystal of SWNTs is obtained by using a series of diamond wire drawing dies. X-ray experiment indicates that the SWNTs arrange in a triangular lattice with a constant of 19.6 angstrom and the properties of SWNT crystal are studied.
2. SWNT energy conversion devices and self-powered system: We show that the water inside SWNT can be driven to… More >

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676

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K. Zhang, H. L. Duan, J. Wang
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 27-28, 2011, DOI:10.3970/icces.2011.018.027
Abstract Recently, much attention has been paid to the single walled carbon nanotube (SWCNT) bundle, which exhibits remarkable mechanical, chemical and electrical properties. Here, we present the pattern transformations of the SWCNT bundle under contraction and expansion. We first report three simple relations governing the geometry of the SWCNT bundle under no pressure. Then, due to the expansion of the bundle, a new hexagonal structure is found by using both the hybrid atom-continuum model and density functional theory. The results show that when the diameter of the nanotubes is larger than certain critical value, the nanotubes in the bundle will undergo… More >

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650

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Zhao Huiming, Dong Zhengzhu, Chen Jiarui, Yang Min
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 29-30, 2011, DOI:10.3970/icces.2011.018.029
Abstract The advantage of the coupling method of natural boundary element method(NBEM) and finite element method (FEM) is introduced firstly. Then the principle of the direct coupling method of NBEM and FEM, and its implementation, are discussed. The comparison of results between the direct coupling method and FEM proves that the direct coupling method is simple, feasible and valid in practice. More >

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661

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Xiang-Ying Ji, Xi-Qiao Feng
The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.1, pp. 31-32, 2011, DOI:10.3970/icces.2011.018.031
Abstract Microtubules experience growing and shrinking alternatively. This dynamic property is intrinsic for microtubules and is essential for them to function. Revealing the mechanism for microtubules to maintain a stable growth phase is important and fascinating. It has been recognized that the hydrolysis of the nucleotides bound on the tubulins and the associated configuration changes of the tubulins highly influence the growth and shrinkage process of microtubules. In consideration of the hydrolysis effect, a "GTP cap" model has been widely supposed to answer for the stabilizing mechanism of microtubule growth. Meanwhile, experiments shown that there exists an open sheet structure curving… More >

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