Parametric design of class 4 steel cross sections - A comparison between the reduced stress method and the effective width method

Abstract

Eurocode provides two different methods to design steel structures in cross section class four which is the effective width method and the reduced stress method. The first mentioned method is the most common method in Sweden and consists of a rather time consuming calculation procedure. The second method results in a rather conservative design. The aim with this thesis is to achieve a better understanding of when and how to use either of the methods, and to achieve an effective design process with the help of a developed design tool. The thesis is conducted by a literature study about the two methods and the existing studies of improved versions of the methods. The literature study is followed by a parametric study where the methods are compared. The reduced stress method is both calculated analytically and combined with the FE-programme Sofistik with its geometry generated with Grasshopper, whereas the effective width method consists of hand calculations.