Francesco Tornabene^*, Matteo Viscoti, Rossana Dimitri

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1393-1468, 2023, DOI:10.32604/cmes.2022.022237

Abstract In the present manuscript, a Layer-Wise (LW) generalized model is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface loads. The unknown field variable is modelled employing polynomials of various orders, each of them defined within each layer of the structure. As a particular case of the LW model, an Equivalent Single Layer (ESL) formulation is derived too. Different approaches are outlined for the assessment of external forces, as well as for non-conventional constraints. The doubly-curved shell is composed by superimposed generally anisotropic laminae, each of them characterized… More >

Francesco Tornabene^*, Matteo Viscoti, Rossana Dimitri

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.3, pp. 719-798, 2022, DOI:10.32604/cmes.2022.022210

Abstract The article proposes an Equivalent Single Layer (ESL) formulation for the linear static analysis of arbitrarily-shaped shell structures subjected to general surface loads and boundary conditions. A parametrization of the physical domain is provided by employing a set of curvilinear principal coordinates. The generalized blending methodology accounts for a distortion of the structure so that disparate geometries can be considered. Each layer of the stacking sequence has an arbitrary orientation and is modelled as a generally anisotropic continuum. In addition, re-entrant auxetic three-dimensional honeycomb cells with soft-core behaviour are considered in the model. The unknown variables are described employing a… More > Graphic Abstract

M. R. Hematiyan^1,*, B. Jamshidi¹, M. Mohammadi²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1349-1369, 2022, DOI:10.32604/cmes.2022.018235

Abstract The method of fundamental solutions (MFS) is a boundary-type and truly meshfree method, which is recognized as an efficient numerical tool for solving boundary value problems. The geometrical shape, boundary conditions, and applied loads can be easily modeled in the MFS. This capability makes the MFS particularly suitable for shape optimization, moving load, and inverse problems. However, it is observed that the standard MFS lead to inaccurate solutions for some elastostatic problems with stress concentration and/or highly anisotropic materials. In this work, by a numerical study, the important parameters, which have significant influence on the accuracy of the MFS for… More >

Taffetani M.¹, Bertarelli E.^1,2, Gottardi R.^3,4, Raiteri R.⁵, Vena P.^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.5, pp. 433-460, 2012, DOI:10.3970/cmes.2012.087.433

Abstract Dynamic nanoindentation is a novel nanomechanical testing that is being increasingly used to characterize the frequency response of viscoelastic materials and of soft hydrated biological tissues at the micrometric and nanometric length scales. This technique is able to provide more information than those obtained by simple indentation; however, its interpretation is still an open issue for complex materials such as the case of anisotropic biological tissues that generally have a high water content. This work presents a numerical model to characterize the frequency response of poro-elastic tissues subjected to harmonic indentation loading with particular regard to the effect of geometrical… More >

P.D. Shah¹, C.L. Tan^1,2, X. Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.13, No.3, pp. 185-198, 2006, DOI:10.3970/cmes.2006.013.185

Abstract In this paper, the path independent mutual or M-integral for the computation of the T-stress for interface cracks between dissimilar anisotropic, linear elastic solids, is developed. The required auxiliary field solution is derived from the solution of the problem of an anisotropic composite wedge subjected to a point force at its apex. The Boundary Element Method (BEM) is employed for the numerical stress analysis in which special crack-tip elements with the proper oscillatory traction singularity are used. The successful implementation of the procedure for evaluating the T-stress in a bi-material interface crack and its application are demonstrated by numerical examples. More >

J. Sladek¹, V. Sladek¹, M. Wünsche², Ch. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.54, No.2, pp. 223-252, 2009, DOI:10.3970/cmes.2009.054.223

Abstract A meshless method based on the local Petrov-Galerkin approach is proposed, to solve the interface crack problem between two dissimilar anisotropic elastic solids. Both stationary and transient mechanical and thermal loads are considered for two-dimensional (2-D) problems in this paper. A Heaviside step function as the test functions is applied in the weak-form to derive local integral equations. Nodal points are spread on the analyzed domain, and each node is surrounded by a small circle for simplicity. The spatial variations of the displacements and temperature are approximated by the Moving Least-Squares (MLS) scheme. After performing the spatial integrations, one obtains… More >

S. D. Harris¹, R. Mustata², L. Elliott², D. B. Ingham², D. Lesnic²

CMES-Computer Modeling in Engineering & Sciences, Vol.25, No.2, pp. 69-80, 2008, DOI:10.3970/cmes.2008.025.069

Abstract Two homogeneous anisotropic materials are butted together to form a contact surface within a single composite material (the specimen). An inverse boundary element method (BEM) is developed to determine the components of the hydraulic conductivity tensor of each material and the position of the contact surface. A steady state flow is forced through the specimen by the application of a constant pressure differential on its opposite faces. Experimental measurements (simulated) of pressure and average hydraulic flux at exposed boundaries are then used in a modified least squares functional. This functional minimises the gap between the above measured (simulated) values and… More >

Chyanbin Hwu¹, T.L. Kuo, Y.C. Chen

CMC-Computers, Materials & Continua, Vol.11, No.3, pp. 165-184, 2009, DOI:10.3970/cmc.2009.011.165

Abstract In this paper the near tip solutions for interface corners written in terms of the stress intensity factors are presented in a unified expression. This single expression is applicable for any kinds of interface corners including corners and cracks in homogeneous materials as well as interface corners and interface cracks lying between two dissimilar materials, in which the materials can be any kinds of linear elastic anisotropic materials or piezoelectric materials. Through this unified expression of near tip solutions, the singular orders of stresses and their associated stress/electric intensity factors for different kinds of interface problems can be determined through… More >