M. Toujani¹, R. Djebali², L. Hassini¹, S. Azzouz¹, A. Belghith¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.5, pp. 469-485, 2014, DOI:10.3970/cmes.2014.098.469

Abstract In the present work we aim to simulate unsteady two-dimensional evolution of the moisture content, temperature and mechanical stress in a parallelepiped apple sample during convective drying. The model is based on the heat and mass transfer equations and the mechanical equilibrium equation under the assumptions of plane deformation, viscoelasticity and isotropic hydric shrinkage. The Finite Elements COMSOL Multiphysics solver is used to solve the developed model. The hydro-thermal model was validated on experimental data drawn in our laboratory for moisture and temperature internal profiles of the product. Excellent agreement has been obtained between numerical More >

Jason F. Hammond¹, Elizabeth J. Stewart², John G. Younger³, Michael J.Solomon², David M. Bortz^4,5

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.3, pp. 295-340, 2014, DOI:10.32604/cmes.2014.098.295

Abstract The overall goal of this work is to develop a numerical simulation which correctly describes a bacterial biofilm fluid-structure interaction and separation process. In this, the first of a two-part effort, we fully develop a convergent scheme and provide numerical evidence for the method order as well as a full 3D separation simulation. We use an immersed boundary-based method (IBM) to model and simulate a biofilm with density and viscosity values different from than that of the surrounding fluid. The simulation also includes breakable springs connecting the bacteria in the biofilm which allows the inclusion… More >

Tao Jiang^1,2, Yuan-Sheng Tang¹, Jin-Lian Ren^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.101, No.4, pp. 249-297, 2014, DOI:10.3970/cmes.2014.101.249

Abstract In this work, a corrected three-dimensional smoothed particle hydrodynamics (CSPH-3D) method is proposed to simulate the polymer free surface flows in the filling process based on the eXtended Pom-Pom (XPP) model, and some complex deformation phenomena are also numerically predicted. The proposed CSPH-3D method is mainly motivated by a coupled concept that an extended kernel-gradient-corrected SPH (KGC-SPH) method is used in the interior of fluid flow and the traditional SPH (TSPH) method is used near the boundary domain. The present 3D particle method has higher accuracy and better stability than the TSPH-3D method. Meanwhile, a… More >

Yidong Bao^1,2, Dongmei Wu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.4, pp. 277-294, 2014, DOI:10.3970/cmes.2014.100.277

Abstract Aiming at the shortcomings of mass-spring model, this paper, on the basis of preliminary studies, established a new viscoelastic soft tissue model based on meshless structure. The model is consisted of a large quantity of filled spheres, with every three spheres being connected by a spring and a Kelvin structure, which can further enhance the real-time virtual simulation operability while ensure the viscoelasticity of basic model. The stress relaxation and creep equation of the model can be derived from formula derivation. Through setting different parameters to the filled spheres, this model, with certain universal property, 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 >

Guanghui Shi¹, Qingsheng Yang^1,2, Xiaoqiao He^3,4, Kim Meow Liew³

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.5, pp. 339-358, 2013, DOI:10.3970/cmes.2013.090.339

Abstract In order to describe the thermomechanical deformation and shape memory effect of shape memory polymers (SMPs), a three-dimensional thermomechanical constitutive model that considers elastic, viscoelastic strain and thermal expansion is proposed for isotropic SMPs. A three-dimensional finite element procedure is developed by implementing the proposed constitutive model into the user material subroutine (UMAT) in ABAQUS program. Numerical examples are used to compare it with existing experimental data in a one dimensional case and to demonstrate the thermomechanical behavior of SMPs with 3D deformation. It is shown that the present constitutive theory and the finite element More >

G. C. Rana¹, R. C. Thakur²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 251-265, 2013, DOI:10.3970/fdmp.2013.009.251

Abstract In this paper, the effect of suspended particles on thermal convection in a compressible viscoelastic fluid hosted in a porous medium is considered. For the porous medium, the Brinkman model is employed with the Rivlin-Ericksen approach used in parallel to describe the rheological behaviour of the viscoelastic fluid. By applying a normal mode analysis method, a dispersion relation is derived and solved analytically. It is observed that the medium permeability, suspended particles, gravity field and viscoelasticity introduce oscillatory modes. For stationary convection, it is found that the Darcy-Brinkman number has a stabilizing effect whereas the More >

Chyanbin Hwu¹, Tai-Liang Kuo²

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 135-153, 2013, DOI:10.3970/cmc.2013.036.135

Abstract The problems of the interface corners between two dissimilar anisotropic viscoelastic materials are studied in this paper. Through the use of the well-known correspondence principle between linear elasticity and linear viscoelasticity, fracture parameters in the Laplace domain can be obtained from the path-independent H-integral for the corresponding problems of anisotropic linear elastic materials. Further application of the correspondence relations for fracture parameters proposed in our recent study then leads us the solutions of fracture parameters in the time domain. To show the applicability and accuracy of the proposed method, several different kinds of numerical examples More >

Jan Heczko¹, Radek Kottner², Tomáš Kroupa²

CMC-Computers, Materials & Continua, Vol.33, No.3, pp. 257-273, 2013, DOI:10.3970/cmc.2013.033.257

Abstract This work deals with mechanical properties of a rubber material that is used in modern tram wheels as a damping element. Nonlinear static response as well as strain softening and hysteresis are captured in the material model that is selected. Method of identification of the model's parameters is developed. The identification method relies on successive minimizations with respect to different sets of parameters. Tests in tension, compression and simple shear are performed. Parameters of the material model are identified based on the tension and compression data, while the shear data are used for validation only. More >

Sandra Deitch^∗, Bruce Z. Gao^†, Delphine Dean^‡

Molecular & Cellular Biomechanics, Vol.9, No.3, pp. 227-250, 2012, DOI:10.3970/mcb.2012.009.227

Abstract Cardiomyocyte phenotype changes significantly in 2D culture systems depending on the substrate composition and organization. Given the variety of substrates that are used both for basic cardiac cell culture studies and for regenerative medicine applications, there is a critical need to understand how the different matrices influence cardiac cell mechanics. In the current study, the mechanical properties of neonatal rat cardiomyocytes cultured in a subconfluent layer upon aligned and unaligned collagen and fibronectin matrices were assessed over a two week period using atomic force microscopy. The elastic modulus was estimated by fitting the Hertz model… More >