Analytical and numerical research of equivalent stabilizing force of stiffened truss chords

Abstract

The aim of this paper is research of the equivalent stabilizing forces of the braced top flange of the truss. The study takes into account the initial bow imperfection e0 of the braced top flange and the im-perfection consisting in a twist of the roof girder’s principal plane by angle ϕ0(x). Moreover, axial force N3(x) in the top flange of the truss is assumed to be longitudinally parabolically variable. The values of the axial forces is: Nsupp in the support zone of the truss and Nspan in the central zone of truss. As part of this study parametric analyses of the equivalent stabilizing forces and the stress of the bracings depending on axial forces Nsupp and Nspan in the braced member were carried out. The results are compared with the results of numerical analyses of 3D models taking the geometric nonlinearity of the structure into account.