SOME CONCEPTUAL ISSUES IN THE MODELLING OF CRACKED BEAMS FOR LATERAL-TORSIONAL BUCKLING ANALYSIS
This paper is focused on the lateral-torsional buckling of cracked or weakened elastic beams. The crack is modelled with a generalized elastic connection law, whose equivalent stiffness parameters can be derived from fracture mechanics considerations. The same type of generalised spring model can be used for beams with semi-rigid connections, typically in the field of steel or timber engineering. As the basis for the present investigation, we consider a strip beam with fork end supports and exhibiting a single vertical edge crack, subjected to uniform bending in the plane of greatest flexural rigidity. The effect of prebuckling deformation is taken into consideration within the framework of the Kirchhoff-Clebsch theory. First, the three-dimensional elastic connection law adopted is a direct extension of the planar case, but this leads to a paradoxical conclusion: the critical moment is not affected by the presence of the crack, regardless of its location. It is shown that the above paradox is due to the non-conservative nature of the connection model adopted. Simple alternatives to this cracked-section constitutive law are proposed, based on conservative moment-rotation laws (quasitangential and semi-tangential) and consistent variational arguments.
Lateral-torsional buckling kirchhoff-clebsch theory connection crack non-conservative loading stability uniform moment variational and energy method spring models
N.Challamel A.Andrade D.Camotim
Universite Europeenne de Bretagne, University of South Brittany UBS LIMATB Centre de Recherche, Rue Department of Civil Engineering—INESC Coimbra, University of Coimbra 3030-788 Coimbra—Portugal Department of Civil Engineering and Architecture—ICIST/IST Technical University of Lisbon, 1049-001
国际会议
The IJSSD Symposium 2012 on Progress in Structural Stability and Dynamics(2012国际结构稳定与动力学进展会议)
南京
英文
9-16
2012-04-14（万方平台首次上网日期，不代表论文的发表时间）