Ning Wang^*

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 33-44, 2010, DOI:10.3970/mcb.2010.007.033

Abstract Professor Y.C. Fung has shown that living tissues remodel extensively in response to mechanical forces such as blood pressure variations. At the cellular level, those mechanical perturbations must be perceived by individual cells. However, mechanisms of mechanochemical transduction in living cells remain a central challenge to cell biologists. Contrary to predictions by existing models of living cells, we reported previously that a local stress, applied via integrin receptors, is propagated to remote sites in the cytoplasm and is concentrated at discrete foci. Here we report that these foci of strains and stresses in the cytoplasm More >

He Gong^∗,†, Ming Zhang^‡

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 1-12, 2010, DOI:10.3970/mcb.2010.007.001

Abstract In mechanical disuse conditions associated with immobilization and microgravity in spaceflight, cortical endosteal surface moved outward with periosteal surface moving slightly or unchanged, resulting in reduction of cortical thickness. Reduced thickness of the shaft cortex of long bone can be considered as an independent predictor of fractures. Accordingly, it is important to study the remodeling process at cortical endosteal surface. This paper presents a computer simulation of cortical endosteal remodeling induced by mechanical disuse at the Basic Multicellular Units level with cortical thickness as controlling variables. The remodeling analysis was performed on a representative rectangular… More >

H.W. Zhang^1,2, J. Lv¹, Y.G. Zheng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.68, No.1, pp. 55-94, 2010, DOI:10.3970/cmes.2010.068.055

Abstract A new multiscale computational method named as extended multiscale finite element method is proposed for the mechanical analysis of closed liquid cell materials. The numerical base functions for both the displacement field and the pressure of the incompressible fluid within the closed cells are employed to establish the relationship between the macroscopic deformation and the microscopic variables such as deformation, stress, strain and fluid pressure. The results show that the extended multiscale finite element method constructed with the conventional four-node quadrilateral coarse-grid elements sometimes will have strong boundary effects and cannot predict well the fluid… More >

E. Carrera, S. Brischetto¹, M. Cinefra²

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.3, pp. 259-342, 2010, DOI:10.3970/cmes.2010.065.259

Abstract This paper investigates the problem of free vibrations of multilayered plates and shells embedding anisotropic and thickness polarized piezoelectric layers. Carrera's Unified Formulation (CUF) has been employed to implement a large variety of electro-mechanical plate/shell theories. So-called Equivalent Single Layer and Layer Wise variable descriptions are employed for mechanical and electrical variables;linear to fourth order expansions are used in the thickness direction z in terms of power of z or Legendre polynomials. Various forms are considered for the Principle of Virtual Displacements (PVD) and Reissner's Mixed Variational Theorem (RMVT) to derive consistent differential electro-mechanical governing… More >

Xianqiao Wang¹, James D. Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.2, pp. 150-170, 2010, DOI:10.3970/cmes.2010.062.150

Abstract The concurrent methods for coupling molecular dynamics with continuum thermodynamics offer a myriad of challenging problems, mostly related with energy transmission, wave reflection, and damage propagation at the interfaces between the continuum description and the discrete description. In this work, by virtue of the atomistic field theory (AFT), we present an analysis to reconcile the compatibility between atomic region and continuum region and to calculate the matching temperature field of a heat conduction problem in a concurrent atomistic/continuum system. First, formulation of AFT with finite temperature and its corresponding finite element implementation are briefly introduced. More >

C. Becker¹, S. Jox², G. Meschke³

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 245-278, 2010, DOI:10.3970/cmes.2010.057.245

Abstract A three-dimensional numerical model based on the Extended Finite Element Method (X-FEM) is presented for the simulation of cohesive cracks in cementitious materials, such as concrete, in a hygro-mechanical framework. Enhancement functions for the small scale resolution of the displacement jump across cracks in the context of the X-FEM is used in conjunction with a higher order family of hierarchical shape functions for the representation of the large scale displacement field of the investigated structure. Besides the theoretical and computational formulation in a multiphase context, aspects of the implementation, such as integration and crack tracking More >

M. Kashtalyan^1,2, Y.A. Zhuk³

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.1, pp. 1-30, 2010, DOI:10.3970/cmes.2010.057.001

Abstract The paper investigates propagation of stationary plane longitudinal and transverse waves along the layers in adhesively bonded multilayered structures for MEMS applications in the presence of residual stresses. The multilayered structure is assumed to consist of the infinite amount of the periodically recurring layers made of two different materials possessing significantly dissimilar properties: conductive metal layer and insulating adhesive layer. It is assumed that the mechanical behaviour of both materials is nonlinear elastic and can be described with the help of the elastic Murnaghan potential depending on the three invariants of strain tensor. The problem More >

S. Brischetto¹, E. Carrera²

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.3, pp. 249-302, 2010, DOI:10.3970/cmes.2010.056.249

Abstract This work considers the fully coupled thermo-mechanical analysis of one-layered and multilayered isotropic and composite shells. The temperature is assumed a primary variable as the displacement; it is therefore directly obtained from the model and this feature permits the temperature field to be evaluated through the thickness direction. Three problems are analyzed: - static analysis of shells with imposed temperature on the external surfaces; - static analysis of shells subjected to a mechanical load, with the possibility of considering the temperature field effects; - a free vibration problem, with the evaluation of the temperature field… More >

G.I. Giannopoulos¹, S.K. Georgantzinos², D.E. Katsareas², N.K. Anifantis²

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.3, pp. 231-248, 2010, DOI:10.3970/cmes.2010.056.231

Abstract A hybrid finite element formulation, combining nanoscopic and macroscopic considerations is proposed, for the prediction of the elastic mechanical properties of single walled carbon nanotube (SWCNT)-based composites. The nanotubes are modeled according to the molecular mechanics theory via the use of spring elements, while the matrix is modeled as a continuum medium. A new formulation concerning the load transfer between the nanotubes and matrix is proposed. The interactions between the two phases are implemented by utilizing appropriate stiffness variations describing a heterogeneous interfacial region. A periodic distribution and orientation of the SWCNTs is considered. Thereupon, More >

Dalin Tang¹, Chun Yang^1,2, Tal Geva^3,4, Glenn Gaudette⁴, and Pedro J. del Nido⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.2, pp. 113-130, 2010, DOI:10.3970/cmes.2010.056.113

Abstract Right and left ventricle (RV/LV) combination models with three different patch materials (Dacron scaffold, treated pericardium, and contracting myocardium), two-layer construction, fiber orientation, and active anisotropic material properties were introduced to evaluate the effects of patch materials on RV function. A material-stiffening approach was used to model active heart contraction. Cardiac magnetic resonance (CMR) imaging was performed to acquire patient-specific ventricular geometries and cardiac motion from a patient with severe RV dilatation due to pulmonary regurgitation needing RV remodeling and pulmonary valve replacement operation. Computational models were constructed and solved to obtain RV stroke volume,… More >