Mikhail Itskov*, Khiȇm Ngoc Vu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.1, pp. 112-112, 2019, DOI:10.32604/icces.2019.05013

Abstract Mechanoluminescence is a phenomenon where broken chemical bonds send out visible light upon stress application. To this end, special mechanophores are added into the polymer network prior to its vulcanization. As such, bis(adamantyl) 1,2-dioxetane can be used. The breakage of the dioxetane cross-linker is irreversible and can directly be used to assess the damage evolution in rubber-like materials. The intensity of the emitted light correlates with the underlying evolution of chain scission in polymers. In this contribution, an anisotropic analytical network-averaging concept [1] is utilized to model mechanoluminescence, Mullins effect, hysteresis and induced anisotropy in… More >

Zhou Zhao¹, Boyan Mao², Youjun Liu², Haisheng Yang², Yu Chen^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.116, No.2, pp. 229-245, 2018, DOI:10.31614/cmes.2018.04192

Abstract In coronary artery bypass grafting (CABG), graft’s poor instant patency may lead to an abnormal hemodynamic environment in anastomosis, which could further cause graft failure after the surgery. This paper investigates the graft hemodynamics with different instant patency, and explores its effect on graft postoperative efficiency. Six CABG 0D/3D coupling multi-scale models which used left internal mammary artery (LIMA) and saphenous vein (SVG) as grafts were constructed. Different types of grafts were examined in the models, including normal grafts, grafts with competitive flow and grafts with anastomotic stenosis. Simulation results indicated that comparing with SVG… More >

Marcin Maździarz¹, Marcin Gajewski²

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.2, pp. 123-150, 2015, DOI:10.3970/cmes.2015.105.123

Abstract In this paper, the choice and parametrisation of finite deformation polyconvex isotropic hyperelastic models to describe the behaviour of a class of defect-free monocrystalline metal materials at the molecular level is examined. The article discusses some physical, mathematical and numerical demands which in our opinion should be fulfilled by elasticity models to be useful. A set of molecular numerical tests for aluminium and tungsten providing data for the fitting of a hyperelastic model was performed, and an algorithm for parametrisation is discussed. The proposed models with optimised parameters are superior to those used in non-linear More >

Taha Sochi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.2, pp. 151-168, 2014, DOI:10.3970/cmes.2014.099.151

Abstract In this paper, a pore-scale network modeling method, based on the flow continuity residual in conjunction with a Newton-Raphson non-linear iterative solving technique, is proposed and used to obtain the pressure and flow fields in a network of interconnected distensible ducts representing, for instance, blood vasculature or deformable porous media. A previously derived analytical expression correlating boundary pressures to volumetric flow rate in compliant tubes for a pressure-area constitutive elastic relation has been used to represent the underlying flow model. Comparison to a preceding equivalent method, the one-dimensional Navier-Stokes finite element, was made and the More >

Yasunori Yusa¹, Shinobu Yoshimura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.1, pp. 87-104, 2014, DOI:10.3970/cmes.2014.099.087

Abstract To speed up the elastic–plastic analysis of a large-scale model with a crack in which plasticity is observed near the crack, the partitioned coupling method is applied. In this method, the entire analysis model is decomposed into two non-overlapped domains (i.e., global and local domains), and the two domains are analyzed with an iterative method. The cracked local domain is modeled as an elastic–plastic body, whereas the large-scale global domain is modeled as an elastic body. A subcycling technique is utilized for incremental analysis to reduce the number of global elastic analyses. For a benchmark More >

V.B.Shim ¹, K. Mithraratne ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 279-294, 2014, DOI:10.32604/cmes.2014.098.279

Abstract The activation of NF-kB is an important precursor in developing melanoma. However the role of mechanical stimulation in the NF-kB activation has not been studied. We used a multiscale computational modeling approach to investigate the role of mechanical stimulation and the skin tissue internal structures in the activation of NF-kB. Our model is made up of three levels – 1) the macro level where a FE model of the Zygomaticus major muscle was developed; 2) the meso level where a micro FE model of the skin block using a sample from human cadaver was developed;… More >

S.M. Pradhan¹, K.S.Katti¹, D.R. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 181-201, 2014, DOI:10.3970/cmes.2014.098.181

Abstract Multiscale modeling of collagen fibril is carried out by incorporating the material properties of collagen obtained from steered molecular dynamics into the finite element model of collagen fibril with inclusion of crosslinks. The results indicate that the nonbonded interactions between collagen and mineral contribute to the significant enhancement of the elastic modulus of collagen fibril at all the crosslink densities in both the low strain and high strain regimes. The crosslinks are found to play an important role in the mechanical response of collagen fibril, the enhancement in elastic modulus ranging from 5-11% for various 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 >

S. Liu¹, X. Liu^2,3, Y. Yuan², P. F. He¹, H. A. Mang^2,4

CMC-Computers, Materials & Continua, Vol.39, No.2, pp. 85-112, 2014, DOI:10.3970/cmc.2014.039.085

Abstract Autogenous shrinkage is defined as the bulk deformation of a closed, isothermal, cement-based material system, which is not subjected to external forces. It is associated with the hydration process of the cement paste. From the viewpoint of engineering practice, autogenous shrinkage deformations result in an increase of tensile stresses, which may lead to cracking of early-age concrete. Since concrete is a multi-phase composite with different material compositions and microscopic configurations at different scales, autogenous shrinkage does not only depend on the hydration of the cement paste, but also on the mechanical properties of the constituents… More >

S. Liu¹, X. Liu², X. F. Guan³, P.F. He¹, Y. Yuan²

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 173-191, 2013, DOI:10.3970/cmes.2013.092.173

Abstract Early performance of mass concrete structures is very sensitive to the thermal expansion characteristics of concrete. As a kind of multi-phase composite, concrete has different material composition and microscopic configuration in different scales. Its thermal expansion coefficient (CTE) depends not only on the physical and mechanical properties of the constituents, but also on their distribution. What’s more, CTE is also time-dependent with the procedure of hydration. This research proposes a stochastic multi-scale model for analyzing CTE of concrete. In the developed model, concrete macro-scale is divided into three different levels: cement paste scale, mortar scale… More >