Zhiwei Gao^1,*, Shuai Zhang¹, Li Hao¹, Ning Cao²

CMC-Computers, Materials & Continua, Vol.58, No.3, pp. 859-878, 2019, DOI:10.32604/cmc.2019.03634

Abstract Balise system is one kind of high-rate point-mode data transmission equipment. It plays an indispensable role in Chinese Train Control System (CTCS), and it has been immigrated and widely used for passenger dedicated lines and high-speed lines. Thus, its working conditions directly affect train operation safety. However, the balise information transmission system (BITS) is based on the principle of electromagnetic induction, and the communication process is susceptible to external electromagnetic interference. Therefore, it is vital to study the influence of transient signal interference on the balise system. This paper builds the up-link model between the… More >

Susom Dutta¹, A. Ramach,ra Murthy², Dookie Kim³, Pijush Samui⁴

CMC-Computers, Materials & Continua, Vol.53, No.2, pp. 157-174, 2017, DOI:10.3970/cmc.2017.053.167

Abstract In the present scenario, computational modeling has gained much importance for the prediction of the properties of concrete. This paper depicts that how computational intelligence can be applied for the prediction of compressive strength of Self Compacting Concrete (SCC). Three models, namely, Extreme Learning Machine (ELM), Adaptive Neuro Fuzzy Inference System (ANFIS) and Multi Adaptive Regression Spline (MARS) have been employed in the present study for the prediction of compressive strength of self compacting concrete. The contents of cement (c), sand (s), coarse aggregate (a), fly ash (f), water/powder (w/p) ratio and superplasticizer (sp) dosage More >

W.Xu¹, A.M. Waas²

CMC-Computers, Materials & Continua, Vol.46, No.3, pp. 165-194, 2015, DOI:10.3970/cmc.2015.046.165

Abstract Plastic deformation and splitting are two important mechanisms of energy dissipation when metal tubes undergo axial crushing. Isotropic J2 plasticity theory combined with a failure criterion is used to model axial splitting and curling of metal tubes undergoing axial crush. The proposed material model is implemented within a finite element (FE) framework using the user material subroutine VUMAT option available in the commercial code ABAQUS. Experimental results from literature are used to validate the model. The predicted splitting and curling patterns as well as the load-displacement response agree well with the experimental observations. The present More >

Weijie Li¹, Haiming Huang^1,2, Bangcheng Ai³, Ye Tian¹

CMC-Computers, Materials & Continua, Vol.43, No.3, pp. 175-196, 2014, DOI:10.3970/cmc.2014.043.175

Abstract Physical and mathematical models are the key to analyze thermal behavior of charring materials in the thermal protection system of reentry vehicles subjected to aerodynamic heating. To explore the thermal behavior of charring ablator, we developed and compared two models (pyrolysis interface model and pyrolysis layer model) with pyrolysis and surface recession. Taking AVCOAT composites as an example, its nonlinear thermal behavior, which are caused by temperature dependent thermal properties, moving interfaces and moving boundary, were simulated using the calculation codes written respectively on the basis of the pyrolysis layer model and the pyrolysis interface More >

R. Lamloumi^1,2, L. Hassini¹, G. L. Lecomte-Nana², M. A. Elcafsi¹, D. Smith²

CMC-Computers, Materials & Continua, Vol.43, No.3, pp. 137-152, 2014, DOI:10.3970/cmc.2014.043.137

Abstract A mathematical model was developed to simulate in 2D the spatiotemporal evolution of the moisture content, the temperature and the mechanical stress within a deformable and saturated product during convective drying. A comprehensive hydro-thermal model had been merged with a Maxwell model with two branches, assuming a viscoelastic material, a plane deformation and an isotropic hydric-shrinkage of the sample. A long sample of clay mixture with a square section was chosen as an application case. The transport and equilibrium properties of the product required for the modeling were determined from previous experiments which were independent More >

J. Joseph¹, Y. C. Lu ¹,

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 63-74, 2014, DOI:10.3970/cmc.2014.042.063

Abstract The super-long, vertically aligned carbon nanotubes (SL-VACNTs) are novel carbon nanomaterial produced from template-free synthesis. The mechanical responses of such material have been investigated by continuum finite element modeling and compared with experimental observations. The crushable foam model has been adequate in modeling the stress-strain curve and deformation of the SL-VACNTs under compression. SL-VACNTs are seen to exhibit transient elastic deformation at small displacement and then plastic deformation at large displacement. The deformation mostly occur at the position immediately beneath the compression platen (indenter face) due to the high stress/strain concentrations. More >

Qiubao Ouyang¹, Di Zhang^1,2, Xinhai Zhu³, Zhidong Han³

CMC-Computers, Materials & Continua, Vol.41, No.1, pp. 37-54, 2014, DOI:10.3970/cmc.2014.041.037

Abstract The present work is to investigate the failure mechanisms in the deformation of silicon carbide (SiC) particle reinforced aluminum Metal Matrix Composites (MMCs). To better deal with crack growth, a new numerical approach: the MLPG-Eshelby Method is used. This approach is based on the meshless local weak-forms of the Noether/Eshelby Energy Conservation Laws and it achieves a faster convergent rate and is of good accuracy. In addition, it is much easier for this method to allow material to separate in the material fracture processes, comparing to the conventional popular FEM based method. Based on a… More >

Trenton M. Ricks¹, Thomas E. Lacy, Jr.^1,2, Brett A. Bednarcyk³, Steven M.Arnold³, John W. Hutchins¹

CMC-Computers, Materials & Continua, Vol.40, No.2, pp. 99-130, 2014, DOI:10.3970/cmc.2014.040.099

Abstract A multiscale modeling methodology was developed for continuous fiber composites that incorporates a statistical distribution of fiber strengths into coupled multiscale micromechanics/ finite element (FE) analyses. A modified twoparameter Weibull cumulative distribution function, which accounts for the effect of fiber length on the probability of failure, was used to characterize the statistical distribution of fiber strengths. A parametric study using the NASA Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) was performed to assess the effect of variable fiber strengths on local composite failure within a repeating unit cell (RUC) and subsequent global… More >

J.B. Niu¹, L.L. Li², Q. Xu¹, Z.H. Xia^1,3

CMC-Computers, Materials & Continua, Vol.38, No.1, pp. 31-41, 2013, DOI:10.3970/cmc.2013.038.031

Abstract Crack deflection and penetration at the interface of multi-wall carbon nanotube/amorphous carbon composites were studied via molecular dynamics simulations. In-situ strength of double-wall nanotubes bridging a matrix crack was calculated under various interfacial conditions. The structure of the nanotube reinforcement -ideal multi-wall vs. multi-wall with interwall sp³ bonding - influences the interfacial sliding and crack penetration. When the nanotube/matrix interface is strong, matrix crack penetrates the outermost layer of nanotubes but it deflects within the nanotubes with certain sp³ interwall bond density, resulting in inner wall pullout. With increasing the sp³ interwall bond density, the fracture mode More >

J. Joseph¹, Y. C. Lu¹

CMC-Computers, Materials & Continua, Vol.37, No.1, pp. 59-75, 2013, DOI:10.3970/cmc.2013.037.059

Abstract The aligned carbon nanotube (A-CNT) structure is composed of arrays of individual CNTs grown vertically on a flat substrate. The overall structure and properties of an A-CNTs are highly dependent upon the designs of various architectures and geometric parameters. In Part 2, we have presented the detailed designs and modeling of various aligned carbon nanotube structures. It is found the A-CNT structures generally have much lower modulus than an individual CNT. The reason is due to the high porosity and low density of the A-CNT structures, since the interstitial space between nanotubes is mostly occupied More >