Liming Xiong¹, Youping Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 203-214, 2008, DOI:10.3970/cmes.2008.024.203

Abstract This paper presents the application of an atomistic field theory (AFT) in modeling and simulation of boron- , boron/nitrogen and silicon/nitrogen-doped nanocrystalline silicon carbide (B-, BN-, SiN-SiC). Intergranular glassy films (IGFs) and nano-sized pores have been obtained in triple junctions of the grains in nanocrystalline SiC (nc-SiC). Residual tensile stress in the SiC grains and compressive stress in the grain boundaries (GBs) are observed. Under uniaxial tension, the constitutive responses of nanocrystalline SiC were reproduced from the simulations. It is found that the mechanical properties of nanocrystalline SiC are strongly dependent on the compositions of More >

Huanchun Chen¹, Kunigal Shivakumar¹

CMC-Computers, Materials & Continua, Vol.8, No.1, pp. 33-42, 2008, DOI:10.3970/cmc.2008.008.033

Abstract Thermal cycling degradation effect on tensile and flexural properties of Cytec T650 carbon/Lonza Primaset PT-30 cyanate ester composite rods used for gas turbine engine brush seals was evaluated. The composite rods were thermal cycled in air from room temperature to 315°C for 100, 200, 400, 600 and 800 cycles. Each thermal cycle is a one hour period with 28 minutes hold at peak temperature and a high heating/cooling rate of 73°C/min. The composite withstood the first 100 thermal cycles with less than 10% property change. After that, tensile strength and fracture strain as well as More >

Xiuqing Qian¹, Yanping Cao², Jianyu Zhang¹, Dierk Raabe², Zhenhan Yao³, Binjun Fei¹

CMC-Computers, Materials & Continua, Vol.7, No.1, pp. 33-42, 2008, DOI:10.3970/cmc.2008.007.033

Abstract In this work, an inverse approach based on depth-sensing instrumented indentation tests is proposed to determine the Young's modulus, yield strength and strain hardening exponent of the materials for which the elastoplastic part of the stress-strain curve can be described using a power function. Numerical verifications performed on typical engineering metals demonstrate the effectiveness of the new method. The sensitivity of the method to data noise and some experimental uncertainties are also discussed, which may provide useful information for the application of the method in practice. More >

R. Matsumoto¹, N. Miyazaki¹, M. Nakagaki²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 223-230, 2007, DOI:10.3970/icces.2007.004.223

Abstract The mechanical properties of amorphous metals and metallic glasses are remarkably changed by precipitated crystalline particles. In this paper, the effects of crystal particle size and volume fraction on the flow stress of the metallic glass are evaluated by molecular dynamics simulations. The investigated volume fraction ranges from 0% (metallic glass) to 100% (nanocrystalline metal), and the average particle diameter ranges from 1nm to 12nm. It is revealed that the dispersed particle effects on the flow stress are very small in the entire volume fraction range when the average particle diameter is smaller than 3 More >

Judith Su^∗, Ricardo R. Brau^†, Xingyu Jiang^‡, George M. Whitesides^§, Matthew J. Lang^¶, Peter T. C. So^||

Molecular & Cellular Biomechanics, Vol.4, No.2, pp. 105-118, 2007, DOI:10.3970/mcb.2007.004.105

Abstract During migration, asymmetrically polarized cells achieve motion by coordinating the protrusion and retraction of their leading and trailing edges, respectively. Although it is well known that local changes in the dynamics of actin cytoskeleton remodeling drive these processes, neither the cytoskeletal rheological properties of these migrating cells are well quantified nor is it understand how these rheological properties are regulated by underlying molecular processes. In this report, we have used soft lithography to create morphologically polarized cells in order to examine rheological differences between the front and rear zone of an NIH 3T3 cell posed More >

Judith Su^∗, Xingyu Jiang^†, Roy Welsch^‡, George M. Whitesides^§, Peter T. C. So^¶

Molecular & Cellular Biomechanics, Vol.4, No.2, pp. 87-104, 2007, DOI:10.3970/mcb.2007.004.087

Abstract Interactions between the cell and the extracellular matrix regulate a variety of cellular properties and functions, including cellular rheology. In the present study of cellular adhesion, area was controlled by confining NIH 3T3 fibroblast cells to circular micropatterned islands of defined size. The shear moduli of cells adhering to islands of well defined geometry, as measured by magnetic microrheometry, was found to have a significantly lower variance than those of cells allowed to spread on unpatterned surfaces. We observe that the area of cellular adhesion influences shear modulus. Rheological measurements further indicate that cellular shear… More >

W.H. Chen¹, H.C. Cheng², Y.C. Hsu³

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.2, pp. 123-146, 2007, DOI:10.3970/cmes.2007.020.123

Abstract The evaluation of the fundamental mechanical properties of single/multi-walled carbon nanotubes(S/MWCNTs) is of great importance for their industrial applications. The present work is thus devoted to the determination of various mechanical properties of S/MWCNTs using molecular dynamics (MD) simulations. The study first focuses on the exploration of the effect of the weak inlayer van der Waals (vdW) atomistic interactions on the mechanical properties of S/MWCNTs. Secondly, in addition to the zig-zag and armchair types of CNTs, the hybrid type of MWCNTs that comprise a zig-zag outer tube and an inner armchair tube is also analyzed.… More >

X. Xin¹, M. Hussain¹, J. Mao¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 187-188, 2006, DOI:10.32604/mcb.2006.003.187

Abstract This article has no abstract. More >

C. N. Rios¹, J. N. Augustine¹, A. B. Mathur¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 173-174, 2006, DOI:10.32604/mcb.2006.003.173

Abstract This article has no abstract. More >

L. Gornet¹, S. Marguet², G. Marckmann³

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 63-74, 2006, DOI:10.3970/cmc.2006.004.063

Abstract The purpose of the present study is to determine the components of the effective elasticity tensor and the failure properties of Nomex^® honeycomb cores. In order to carry out this study, the NidaCore software, a program dedicated to Nomex®Cores predictions, has been developed using the Finite Element tool Cast3M-CEA. This software is based on periodic homogenization techniques and on the modelling of structural instability phenomena. The homogenization of the periodic microstructure is realized thanks to a strain energy approach. It assumes the mechanical equivalence between the microstructures of a RVE and a similar homogeneous macroscopic volume.… More >