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Composite bars of arbitrary cross section in nonlinear elastic nonuniform torsion by BEM / Sapountzakis, E. J. in Journal of engineering mechanics, Vol. 135 N° 12 (Décembre 2009) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 135 N° 12 (Décembre 2009) . - pp. 1354-1367 Titre : Composite bars of arbitrary cross section in nonlinear elastic nonuniform torsion by BEM Type de document : texte imprimé Auteurs : Sapountzakis, E. J., Auteur ; Tsipiras, V. J., Auteur Article en page(s) : pp. 1354-1367 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Bars  Torsion  Geometry  Shear  stress  Warpage  Boundaries  Cross  sections. Résumé : In this paper the elastic nonuniform torsion analysis of composite cylindrical bars of arbitrary cross section consisting of materials in contact, each of which can surround a finite number of inclusions, taking into account the effect of geometric nonlinearity is presented employing the boundary element method (BEM). All of the cross section's materials are perfectly bonded together, that is separation is not allowed. The torque-rotation relationship is computed based on the finite displacement (finite rotation) theory, that is the transverse displacement components are expressed so as to be valid for large rotations and the longitudinal normal strain includes the second-order geometric nonlinear term often described as the “Wagner strain.” The proposed formulation does not stand on the assumption of a thin-walled structure and therefore the cross section's torsional rigidity is evaluated exactly without using the so-called Saint-Venant's torsional constant. The torsional rigidity of the cross section is evaluated directly employing the primary warping function of the cross section depending on its shape. Three boundary value problems with respect to the variable along the beam axis angle of twist, to the primary and to the secondary warping functions are formulated. The first one, employing the Analog Equation Method (a BEM based method), yields a system of nonlinear equations from which the angle of twist is computed by an iterative process. The rest two problems are solved employing a pure BE method. Numerical results are presented to illustrate the method and demonstrate its efficiency and accuracy. The developed procedure retains most of the advantages of a BEM solution over a pure domain discretization method, although it requires domain discretization. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&smode=strres [...] [article] Composite bars of arbitrary cross section in nonlinear elastic nonuniform torsion by BEM [texte imprimé] / Sapountzakis, E. J., Auteur ; Tsipiras, V. J., Auteur . - pp. 1354-1367. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 135 N° 12 (Décembre 2009) . - pp. 1354-1367 Mots-clés : Bars  Torsion  Geometry  Shear  stress  Warpage  Boundaries  Cross  sections. Résumé : In this paper the elastic nonuniform torsion analysis of composite cylindrical bars of arbitrary cross section consisting of materials in contact, each of which can surround a finite number of inclusions, taking into account the effect of geometric nonlinearity is presented employing the boundary element method (BEM). All of the cross section's materials are perfectly bonded together, that is separation is not allowed. The torque-rotation relationship is computed based on the finite displacement (finite rotation) theory, that is the transverse displacement components are expressed so as to be valid for large rotations and the longitudinal normal strain includes the second-order geometric nonlinear term often described as the “Wagner strain.” The proposed formulation does not stand on the assumption of a thin-walled structure and therefore the cross section's torsional rigidity is evaluated exactly without using the so-called Saint-Venant's torsional constant. The torsional rigidity of the cross section is evaluated directly employing the primary warping function of the cross section depending on its shape. Three boundary value problems with respect to the variable along the beam axis angle of twist, to the primary and to the secondary warping functions are formulated. The first one, employing the Analog Equation Method (a BEM based method), yields a system of nonlinear equations from which the angle of twist is computed by an iterative process. The rest two problems are solved employing a pure BE method. Numerical results are presented to illustrate the method and demonstrate its efficiency and accuracy. The developed procedure retains most of the advantages of a BEM solution over a pure domain discretization method, although it requires domain discretization. DEWEY : 620.1 ISSN : 0733-9399 En ligne : http://ascelibrary.aip.org/vsearch/servlet/VerityServlet?KEY=JENMDT&smode=strres [...]