Unbraced steel frame design according to EC3 and AISC provisions: Fid-Bau Portal

Unbraced steel frame design according to EC3 and AISC provisions

Bernuzzi, Claudio / Cordova, Benedetto / Simoncelli, Marco

Abstract One of the main results of increasing globalization is that nowadays design, fabrication and erection of steel structures can take place at different locations potentially separated by several thousand kilometres. As a consequence, owners might require the use of widely accepted steel design codes and designers should therefore be familiar with alternative specifications that may be substantially different from one another. The paper deals with unbraced steel frames, and presents a comparison between the rules adopted by the European and United States design provisions. After a brief discussion on the key features of both codes, attention is focussed mainly on the different approaches to structural analysis. Furthermore, the results of a parametric study are described, highlighting the differences associated with the permissible design alternatives in terms of load carrying capacity. Reference is made to planar frames with differing geometry, load conditions, imperfection modelling and degree of the rotational stiffness of beam-to-column joints. Finally, Appendix A proposes a benchmark example reporting all details associated with the application of the design approaches under consideration.

Highlights • designers use nowadays structural specifications characterized by substantial differences between each other; • a direct comparison between the rules adopted by the European and United States design provisions has been developed; • the imperfection modelling via notional loads or non-perfect frames has a negligible influence on the frame performance; • one European approach (EC3-RAM) leads to a relevant overestimation of the values of the load carrying capacity; • with the exception of EC3-RAM, EU and US design alternatives are substantially equivalent from a design point of view;