Effect of axial restraint in composite bars under nonlinear inelastic uniform torsion by BEM

Sapountzakis, EJ; Tsipiras, VJ

dc.contributor.author	Sapountzakis, EJ	en
dc.contributor.author	Tsipiras, VJ	en
dc.date.accessioned	2014-03-01T01:30:15Z
dc.date.available	2014-03-01T01:30:15Z
dc.date.issued	2009	en
dc.identifier.issn	0141-0296	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19520
dc.subject	Axial restraint	en
dc.subject	Beam	en
dc.subject	Boundary element method	en
dc.subject	Composite bar	en
dc.subject	Elastoplastic	en
dc.subject	Inelastic	en
dc.subject	Plastic	en
dc.subject	Shear stresses	en
dc.subject	Twist	en
dc.subject	Uniform torsion	en
dc.subject	Wagner strain	en
dc.subject	Warping	en
dc.subject.classification	Engineering, Civil	en
dc.subject.other	Axial flow	en
dc.subject.other	Differential equations	en
dc.subject.other	Elastoplasticity	en
dc.subject.other	Plastics	en
dc.subject.other	Rigidity	en
dc.subject.other	Rotation	en
dc.subject.other	Shear stress	en
dc.subject.other	Strain	en
dc.subject.other	Strain hardening	en
dc.subject.other	Strength of materials	en
dc.subject.other	Stress-strain curves	en
dc.subject.other	Thin walled structures	en
dc.subject.other	Torsional stress	en
dc.subject.other	Weaving	en
dc.subject.other	Axial restraint	en
dc.subject.other	Beam	en
dc.subject.other	Composite bar	en
dc.subject.other	Elastoplastic	en
dc.subject.other	Inelastic	en
dc.subject.other	Twist	en
dc.subject.other	Uniform torsion	en
dc.subject.other	Wagner strain	en
dc.subject.other	Warping	en
dc.subject.other	Boundary element method	en
dc.subject.other	boundary element method	en
dc.subject.other	nonlinearity	en
dc.subject.other	rigidity	en
dc.subject.other	shear stress	en
dc.subject.other	stress-strain relationship	en
dc.subject.other	torsion	en
dc.title	Effect of axial restraint in composite bars under nonlinear inelastic uniform torsion by BEM	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.engstruct.2009.01.017	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.engstruct.2009.01.017	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	In this paper, the effect of axial restraint in the elastic-plastic uniform torsion analysis of cylindrical bars taking into account the effect of geometric nonlinearity is presented employing the boundary element method. The bar is axially elastically supported at the centroids of its end cross sections, treating the cases of free axial boundary conditions (vanishing axial force), restrained axial shortening or given axial force as special ones. The cross section of the bar is an arbitrary doubly symmetric composite one, consisting of materials in contact, each of which can surround a finite number of inclusions, while the case of a homogeneous cross section is treated as a special one. The stress-strain relationships for the materials are assumed to be elastic-plastic-strain hardening. The incremental 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 geometrically 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 both its shape and the progress of the plastic region. A boundary value problem with respect to the aforementioned function is formulated and solved employing a BEM approach. The developed procedure retains most of the advantages of a BEM solution over a pure domain discretization method, although it requires domain discretization, which is used only to evaluate integrals. The significant increase of the torsional rigidity of the bar and the arising axial force due to the axial restraint are concluded. © 2009 Elsevier Ltd. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	Engineering Structures	en
dc.identifier.doi	10.1016/j.engstruct.2009.01.017	en
dc.identifier.isi	ISI:000265998500018	en
dc.identifier.volume	31	en
dc.identifier.issue	5	en
dc.identifier.spage	1190	en
dc.identifier.epage	1203	en