INFLUENCE OF LOCAL POSTBUCKLING BEHAVIOR ON BENDING OF THIN-WALLED-BEAMS

The influence of the local postbuckling behaviour on the bending of th in-walled beams is studied. The analysis of the postbuckling behaviour of a prismatic column-beam subject to compression and bending is empl oyed in order to determine the overall flexural stiffness of a beam af ter local buckling. The asymptotic Koiter method is used in the second order approximation. The determination of post-buckling coefficients enables one to find the beam's flexural stiffness without the necessit y of ruing hypotheses on effective widths of eccentrically compressed plates. It is shown that the post-buckling equilibrium branch in a ben ding moment - global curvature coordinate system for a perfectly elast ic thin-walled beam is rectilinear (in the second order approximation of the asymptotic method), Simple analytical relations are presented b etween the slope of the post-buckling equilibrium branch of global ben ding and post-buckling coefficients for local buckling mode. The resul ts obtained are compared with data reported by other authors. Copyrigh t (C) 1996 Elsevier Science Ltd.