The rotation-free BST shell element for linearized buckling analysis of steel structures

Published in International Journal for Computational Methods in Engineering Science and Mechanics, Vol. 7 (3), pp. 209-215
DOI: 10.1080/15502280600596646

Abstract

In this paper the ability of the basic shell triangular (BST) element to perform linearized buckling analysis is evaluated. The results have been compared with analytical solutions and other finite elements in the literature, such as ANDES3, ANDES4, QSEL, FFQC and BCIZ. This type of analysis is applied to the design of steel structures to obtain the collapse load of panels using the effective width of the plate. In this approach, which is currently recommended by most of the design standards, a semi-empirical/analytical method is used to take into account the nonlinear geometric and material behavior, geometric imperfections and residual stresses. To obtain the critical loads two methods have been mainly applied: the finite strip method and the finite element method, which is more appropriate to deal with any boundary condition and loading pattern. In practice, to obtain the local and distortional buckling, some assumptions related to the interaction between plates are made in order to obtain practical formulae that can be applied; these simplifications can lead to unsafe results, so the linearized buckling analysis must be carried out in a proper way, taking into account the interactions. It is concluded that the BST element presents an excellent behavior to predict the critical loads in compression and shear, and therefore this element must be utilized in future codes when this type of analysis turn out to be mandatory.