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ABSTRACT

Yusuke Kinoshita¹, Shin Hase¹, Nobutada Ohno¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 39-40, 2009, DOI:10.3970/icces.2009.010.039
Abstract Boron nitride nanotubes (BNNTs) have been found to be truly electrically insulating regardless of their diameters, chiralities and number of shells. On the other hand, a recent experimental work on multi-walled BNNTs has shown that electrical transport properties of the BNNTs change from insulating to semiconducting through a bending deformation. However, deformation-induced electrical effects in BNNTs have not been fully clarified yet. In the present work, HOMO-LUMO energy gaps of (5,0), (13,0), (21,0) single-walled BNNTs (SWBNNTs) and (5,0)@(13,0), (13,0)@(21,0) double-walled BNNTs (DWBNNTs) under flattening deformation have been investigated using first-principles density functional calculations. The LUMO More >

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1130

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853

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ABSTRACT

S. M. Beden¹, S. Abdullah¹, A. K. Ariffin¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 41-50, 2009, DOI:10.3970/icces.2009.010.041
Abstract Fatigue crack growth as consequence of service loads depends on many different contributing factors. This paper describes the fatigue crack growth behavior of metallic materials under cyclic loading towards standardizing the fatigue crack studies on metallic materials. For the simulation purpose, three points bend (TPB) with span to width ratio 8:1 and compact tension (CT) specimens geometry were used. There are many factors affecting the fatigue crack growth in structures, such as fatigue crack growth model, stress ratio, aspect ratio and type of geometry. The behavior of such cases is shown using different fatigue crack More >

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1053

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798

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ABSTRACT

Youngmin Lee, Jae Shin Park, Seyoung Im
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 51-52, 2009, DOI:10.3970/icces.2009.010.051
Abstract We study energetics and mobility of dislocations in silicon crystal in atomistic scale. The electronic structure of silicon affects its dynamics, so that it is analyzed with tight-binding method for high accuracy, emerged as a useful method for studying structural and dynamical properties of covalent systems. The tight biding potential used for silicon crystalline is the one of GSP known as a transferable potential. Due to the nature of rare events, the analysis is executed by action-derived molecular dynamics (ADMD) calculations. The changes of the system energy due to dislocation glide are explored with a More >

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1137

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742

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ABSTRACT

Dongwoo Sohn¹, Jae Hyuk Lim², Young-Sam Cho³, Seyoung Im¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 53-54, 2009, DOI:10.3970/icces.2009.010.053
Abstract A novel multiscale finite element (FE) scheme is proposed for a simulation of crack propagation in the heterogeneous media including randomly distributed microstructures, such as voids, rigid fibers. A fine scale mesh is employed to capture the singularity of the crack tip and the effect of microstructures at the vicinity of crack tip. On the other hand, a region far from the crack tip is composed of coarse scale mesh, wherein the effect of the microstructures is averaged through the homogenization theory. An interface between the fine scale mesh and the coarse scale mesh is More >

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1114

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786

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ABSTRACT

Hong-Ching Her¹, Jin H. Huang¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 55-56, 2009, DOI:10.3970/icces.2009.010.055
Abstract To play melodious sound, a microspeaker in a cellular phone needs to generate wide, smooth sound-pressure-level distribution over the mid-frequency spectrum, ranging from 600 Hz to 10 kHz. In this paper, parametric study is carried out to investigate the effect of various design parameters on the sound-pressure-level distribution. The electro-mechano-acoustical analogous approach is applied to simulate the sound-pressure-level. Also, experiments are conducted for verifications. Discussions about each role of the design parameters are addressed to improve the overall sound-pressure-level performance over the mid-frequency spectrum. More >

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1189

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779

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J. Kong¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 57-64, 2009, DOI:10.3970/icces.2009.010.057
Abstract For the analysis of prismatic thin-walled structures, whether single or continuous spanned, the finite strip method is one of the most effective methods developed to date. Significant development of the method has been made, in particular, by adopting various analytical functions in the longitudinal direction to suit various support conditions, including the classical beam vibration functions and the spline functions. In contrast to analytically-defined functions, an alternative finite strip method is presented herein by exploring the use of computed beam vibration functions that takes into consideration explicitly the axial-bending coupling effect of unsymmetrical, cross-ply laminates More >

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1062

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776

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Tae Soo Kim¹, Pa Ul Mun¹, Myung Kuk Lee¹, Jae Soo Kim^1,2
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 65-70, 2009, DOI:10.3970/icces.2009.010.065
Abstract This article has no abstract. More >

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1167

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889

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T. Tsutsui¹, H. Obiya¹, K. Ijima¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 71-76, 2009, DOI:10.3970/icces.2009.010.071
Abstract This study shows an algorithm, which solves the contact phenomenon without friction with large deformation for plane frame structures. Particularly, the study mentions about a technique for the case when contact node slide to the next-door element from edge of the contact element. The technique is to use the re-division and uniting of the element, in order to avoid the computational unstable territory around the edge of the contact element. Furthermore the authors consider about unstable territory of the contact point by some numerical examples. More >

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1020

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832

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Chih-Chang Chang, Ruey-Jen Yang¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 77-86, 2009, DOI:10.3970/icces.2009.010.077
Abstract This paper presents a theoretical investigation into chaotic mixing in low Reynolds number electro-osmotic flows. In this mixing system, the primary flow is the plug-like electro-osmotic flow contributed by the permanent surface charge at the wall, and the secondary electro-osmotic flows (or electro-osmotic recirculating rolls) contributed by the field-effect-induced surface charge act as the perturbed flow. By time-periodic switching two different secondary electro-osmotic flows, it makes streamlines to cross at successive intervals and results in chaotic mixing. Dynamic system techniques such as Poincaré map and finite-time Lyapunov exponent analyses are employed to describe the behaviors More >

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1032

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846

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Keerasut Suttanarak¹, Nirut Naksuk², Jarruwat Charoensuk¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 87-88, 2009, DOI:10.3970/icces.2009.010.087
Abstract The water management in Proton Exchange Membrane (PEMFC) is crucial in operating PEMFC system concerning water balance between electrode and membrane. Improper cell humidification might lead to drying or flooding of the electrodes, which degrades cell performance. In this research, effects of gas humidification are studied to aid a system designer in achieving the optimal condition of fuel cell system. The investigation takes into account the conservation of mass, momentum, energy and species as well as the water transport equations including electro-osmotic drag and back diffusion through numerical simulation. More >

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834