Hao-Miao Zhou¹, Fang Li¹, Qiang Ye¹, Ji-Xiang Zhao¹, Zhe-Lei Xia¹, YingTang², Jing Wei³

CMC-Computers, Materials & Continua, Vol.13, No.3, pp. 235-248, 2009, DOI:10.3970/cmc.2009.013.235

Abstract At present, there are many methods about Young's modulus measurement of thin films, but so far there is no recognized simple, non-destructive and cheaper standard measurement method. Considering thin films with various thicknesses were sputter deposited on the magnetostrictive resonator and monitoring the resonator's first-order longitudinal resonant frequency shift both before and after deposition induced by external magnetic field, an Young's modulus assessing method based on classical laminated plate theory is presented in this paper. Using the measured natural frequencies of Au, Cu, Cr, Al and SiC materials with various thicknesses in the literature, the More >

Silieti, M.¹, Divo, E.², Kassab, A.J.¹

CMC-Computers, Materials & Continua, Vol.12, No.2, pp. 121-144, 2009, DOI:10.3970/cmc.2009.012.121

Abstract A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling… More >

D. S. Liu¹, C. Y. Tsai¹, S. R. Lyu²

CMC-Computers, Materials & Continua, Vol.11, No.2, pp. 147-164, 2009, DOI:10.3970/cmc.2009.011.147

Abstract This study presents a novel numerical method for extracting the tempe -rature-dependent mechanical properties of the gold and aluminum thin-films. In the proposed approach, molecular dynamics (MD) simulations are performed to establish the load-displacement response of the thin substrate nanoindented at temperatures ranging from 300-900 K. A simple but effective procedure involving genetic algorithm (GA) and finite element method (FEM) is implemented to extract the material constants of the gold and aluminum substrates. The material constants are then used to construct the corresponding stress-strain curve, from which the elastic modulus, yield stress and the tangent More >

Syh-Tsang Jenq^1,2, Yuen-Sheng Chiu²

CMC-Computers, Materials & Continua, Vol.11, No.1, pp. 33-58, 2009, DOI:10.3970/cmc.2009.011.033

Abstract Current work studies the transient hydroplaning behavior of 200 kPa inflated pneumatic radial tires with various types of tread patterns. Tires were numerically loaded with a quarter car weight of 4 kN, and then accelerated from rest rolling over a water film with a thickness of 5, 10 and 15 mm on top of a flat pavement. Tire structure is composed of outer rubber tread and inner fiber reinforcing composite layers. The Mooney-Rivlin constitutive law and the classical laminated theory (CLT) were, respectively, used to describe the mechanical behavior of rubber material and composite reinforcing… More >

Jin-Ho Roh¹, In Lee²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 13-30, 2008, DOI:10.3970/cmes.2008.026.013

Abstract A methodology to maintain the configuration of inflated membrane structures using shape memory alloy (SMA) film actuator is numerically investigated. The two- dimensional incremental formulation of the SMA constitutive model is developed. New parameters related to the thermodynamic energy equation are introduced to describe more general behaviors of the SMA film. With numerical algorithm of wrinkling and SMAs, the interactions between the inflated membrane structure and the SMA film are investigated by using a finite element program. The effectiveness of SMA film to control the configuration of an inflated membrane structure is examined. To demonstrate More >

Arun K. Nair¹, Diana Farkas², Ronald D. Kriz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 239-248, 2008, DOI:10.3970/cmes.2008.024.239

Abstract The indentation response of Ni thin films of thicknesses in the nano scale was studied using molecular dynamics simulations with embedded atom method (EAM) interatomic potentials. Simulations were performed in single crystal films in the [111] orientation with thicknesses of 7nm and 33nm. In the elastic regime, the loading curves observed start deviating from the Hertzian predictions for indentation depths greater than 2.5% of the film thickness. The observed loading curves are therefore dependent on the film thickness. The simulation results also show that the contact stress necessary to emit the first dislocation under the More >

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 >

I. Ueno¹, T. Konisho², T. Kawase³, T. Watanabe⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 21-26, 2008, DOI:10.3970/fdmp.2008.004.021

Abstract The present authors carried out an experimental study with a special interest upon the dynamics of the fluid in the vicinity of the boundary line of three phases; solid-liquid-gas interface, which is so-called `contact line.' The moving droplet on the solid substrate is accompanied with the movement of the boundary line of three phases; solid-liquid-gas interface, which is so-called macroscopic 'contact line.' Existing studies have indicated there is a thin liquid film known as 'precursor film' ahead the contact line of the droplet. In the present study the precursor film was detected by applying conventional More >

A. A. Nepomnyashchy^1,2, I. B. Simanovskii¹

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 185-198, 2008, DOI:10.3970/fdmp.2008.004.185

Abstract The development of instabilities under the joint action of the van der Waals forces and Marangoni stresses in a two-layer film on a heated or cooled substrate is considered. It is found that heating from below leads to the acceleration of the decomposition, decrease of the characteristic lateral size of structures, and the increase of the droplets heights. Heating from above leads to slowing down the instability rate and eventually to a complete suppression of the instability. More >

Walter Gerstle¹, Stewart Silling², David Read³, Vinod Tewary⁴, Richard Lehoucq⁵

CMC-Computers, Materials & Continua, Vol.8, No.2, pp. 75-92, 2008, DOI:10.3970/cmc.2008.008.075

Abstract A theoretical framework, based upon the peridynamic model, is presented for analytical and computational simulation of electromigration. The framework allows four coupled physical processes to be modeled simultaneously: mechanical deformation, heat transfer, electrical potential distribution, and vacancy diffusion. The dynamics of void and crack formation, and hillock and whisker growth can potentially be modeled. The framework can potentially be applied at several modeling scales: atomistic, crystallite, multiple crystallite, and macro. The conceptual simplicity of the model promises to permit many phenomena observed in microchips, including electromigration, thermo-mechanical crack formation, and fatigue crack formation, to be More >