Ye-Shuang Xu, Shui-Long Shen, Jin-Chun Chai, Zhen-Shun Hong

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 65-66, 2011, DOI:10.3970/icces.2011.020.065

Abstract With the process of urbanization, a large amount of infrastructures, e.g. metro tunnels, underground path, and building basement, is constructed in underground along coastal mega-cities, e.g. Shanghai, Tianjin, and Guangzhou etc. The existence of underground in aquifers within the urban region obstructs the behavior of seepage and results in the raise of groundwater level at the upper side and drawdown of groundwater level at the lower side of the structure. Therefore, rebound at the upper side and settlement at the lower side of underground structures may occur due to consolidation in long-term and redistribution of… More >

Dehao Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 63-64, 2011, DOI:10.3970/icces.2011.020.063

Abstract In many fields of scientific and engineering computing the Artificial Boundary Method has been widely applied to solve boundary value problems of partial differential equations, especially it is a very important method for solving problems on unbounded domains. This method is first suggested by K. Feng and D. Yu, called the natural boundary element method, and then also called DtN method by J.B. Keller and D. Givoli. The exact artificial boundary condition is the natural boundary integral equation on the artificial boundary, that is just the Dirichlet to Neumann mapping.

The natural boundary integral equation… More >

Zheng Yi Wu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 60-62, 2011, DOI:10.3970/icces.2011.020.060

Abstract Infrastructure system analysis is a computation-intensive task. Equipped with the software tools, engineers are able to analyze a handful of alternative solutions, but often end up with a workable alternative far from the optimized solution. Effectively optimizing an infrastructure system is a challenging task. Undertaking such a task requires not only well-developed optimization software tools, but also powerful computing facilities. Therefore, infrastructure system optimization is highly desirable to be conducted on cloud.
Infrastructure system optimization is usually an implicit and nonlinear programming problem. The problem has to be carefully formulated in the way that classic mathematic… More >

Zhenxing Hu, Huimin Xie, Jian Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 57-59, 2011, DOI:10.3970/icces.2011.020.057

Abstract Residual stress plays an important role in structural and material manufacturing. Measurement techniques of residual stress can be neatly divided into destructive and non-destructive ones. The destructive techniques are dependent on inferring the original stress from the displacement incurred by completely or partially relieving the stress by removing material. The hole drilling method for residual stress measurement is a destructive method and was first introduced in the 1930s by Mathar. In recent years, the hole drilling method for evaluating residual deformation has been implemented with optical method such as holographic interferometry, electronic speckle pattern interferometry,… More >

Vijay Kumar Gupta

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 55-56, 2011, DOI:10.3970/icces.2011.020.055

Abstract Various applications of piezoelectric actuators have been explored over the years. One such application is use of piezoelectric actuators for shape control of structures. In this paper, steering of parabolic antenna by deforming the antenna surface using piezoelectric actuators has been explored. Optimization based on Genetic Algorithm is carried out to find out optimum location, length and applied electric field to the piezoelectric actuators to achieve desired steering of antenna. Constraints are included in the objective function using penalty approach. Shell finite element model is used to determine deformations induced by the actuators. As the More >

I-Yao CHAN, Chein-Shan Liu, Weichung Yeih

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 53-54, 2011, DOI:10.3970/icces.2011.020.053

Abstract In this study, we adopt the fictitious time integration method to treat the image reconstruction problem. The distorted image is considered as a result of diffused data from the initial perfect image by using a nonlinear diffusion equation. The image reconstruction problem then becomes an inverse problem by using the data in the final time to recover the data in the initial time. This inverse problem is known as the backward in time nonlinear diffusion problem which is highly ill-posed. We propose to use the fictitious time integration method to tackle this highly ill-posed image More >

Lin Yifeng, Zhu Hehua, Cai Yongcang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 51-52, 2011, DOI:10.3970/icces.2011.020.051

Abstract Shield tunnel linings compose of segments , bolts, liners, et.al., which are quite different in geometry and mechanics. Traditional beam-spring joint model and shell-spring joint model is hard to simulate accurately the detailed characteristic. Classical three-dimensional FEM may cause serious mesh-generation difficulty and expensive calculation cost. Based on generalized finite element method and characteristics of shield tunnel, a three-dimensional shield tunnel structure model is established. In the proposed model a sixteen-node solid-shell generalized FE is devised and employed to simulate segments. Joints between segments or rings are modeled with a surface to surface contact generalized… More >

Yohei Inoue, Taishi Nakamura, Shuji Ogata, Ryo Kobayashi, Toshiyuki Gotoh

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 49-50, 2011, DOI:10.3970/icces.2011.020.049

Abstract No proper simulation method exists in between the molecular simulation method at nanometer scale using the first principles or empirical inter-molecular interaction and the continuum simulation method at micrometer-plus scale. The nanotechnology deals principally with those systems whose characteristic scales reside in such a scale-gap. Considering this, we develop a sequential scale-up scheme starting from the atomistic up to micrometer-plus scales. In the present paper we take, as an example, the system of graphenes that may or may not be fluttering in airflow, and apply to it our sequential scale-up scheme to see its capability.

… More >

Hongyang Li, Cheng Chen, WeiWei Li, Yanjing Zhang, Xiaopeng Liu, Yandong Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 47-48, 2011, DOI:10.3970/icces.2011.020.047

Abstract Large numbers of micro lattice plastic deformation of grains set up the macro plastic deformation of polycrystal metallic materials under different macro boundary condition. And the macro homogeneous deformation is in fact the statistical result of micro anisotropic lattice plastic flow. Both of the macro and micro deformation were influenced by intrinsic initial stress, which was intrinsic in the component from micro scale impurity to macro scale non-uniform deformation. In this paper, focused on the engineering application and further damage evaluation, effect of macro initial stress on the macro and micro plasticity deformation of sample More >

A.Y.Chen, J. Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 45-46, 2011, DOI:10.3970/icces.2011.020.045

Abstract The structural reliability of many brittle materials such as nanomaterials relies on the occurrence of intergranular, as opposed to transgranular, fracture in order to induce toughening by crack bridging. The current work examines the role of interface strength and grain size distribution in promoting intergranular fracture in order to maintain high toughening. A layered nanostructural 304SS sheet characterized by periodic distribution of nanocrystalline layers and micron-grained layers with graded grain size evolution has exhibited exceptional properties. The in situ SEM observations illustrate that an intergranular path and the consequent interface bridging process can be partitioned More >