FSplines: A Software for Linear Stability Analysis of Thin-Walled Structures, Version 2.0

Abstract

FSplines is a (geometrically) linear stability analysis tool of thin-walled structures with open section (useful for cold-formed steel profiles), that enables obtaining the bifurcation stresses (critical stress, load and moment) and the respective buckling modes by the Finite Strip Method (FSM).

The Finite Strip Method: (i) allows analyzing prismatic steel members (commercial structural profiles), (ii) is an alternative to the Finite Element Method (FEM), and (iii) has some important advantages over FEM. In the present article, two variants of the FSM are presented: (i) the Semi-Analytical Finite Strip Method (SAFSM), where use is made of trigonometric functions and (ii) the Splines Finite Strip Method (SFSM), employing spline functions. The SAFSM has the advantage of being less time consuming. Its main restriction is the fact that it only allows modelling simple supported members (pinned restrained). The SFSM most important advantage is the ability to model members with all kinds of boundary conditions. This method is, however, more time consuming.

It is worth noting that the bifurcation analysis, performed by the computer application FSplines, is required for the design of cold formed members according to the specifications of international standards.

FSplines 2.0 is the second version of the computer application here presented. In this second improved version more cross-sections are available, and more section properties are presented.