The final draft of the EN version of part 1.1 of Eurocode 3 has introduced significant changes in the evaluation of the lateral-torsional buckling resistance of unrestrained beams at room temperature that reduce the over-conservative approach of ENV 1993-1-1 in the case of non-uniform bending.Numerical modelling of the lateral-torsional buckling of steel beams at elevated temperature has shown that the beam design curve from prEN 1993-1-2 is over-conservative for loadings other than uniform bending.In line with the safety format of the lateral-torsional buckling code provisions for cold design, an alternative proposal for rolled sections or equivalent welded sections subjected to fire is presented in this paper, that addresses the issue of the influence of the loading type on the resistance of the beam, achieving better agreement with the real behaviour while maintaining safety.

Recent experimental evidence has shown that steel joints exhibit a distinct change in their moment-rotation response under increasing temperature. In terms of cold design, the component method is currently the widely accepted procedure for the evaluation of the various design values. It is the purpose of the present paper to extend the component method to the prediction of the response of steel joints under fire loading. Using typical mechanical models consisting of extensional springs and rigid links, whereby the springs exhibit a non-linear force deformation response (here taken as a bi-linear approximation), an analytical procedure is proposed capable of predicting the moment-rotation response under fire conditions that incorporates the variation of yield stress and Young's modulus of the various components as the temperature increases. An application to a cruciform flush end-plate beam-to-column steel joint is presented and compared to the experimental results obtained under various loading conditions.

In this article, the passive thermal performance of a light steel residential building is studied. A numerical model is implemented and is experimentally validated. The analysis is focussed on the Csb climatic region. Subsequently, this calibrated model is used to assess the importance of several parameters (ventilation, thermal insulation, overhangs shading, windows shade devices, and windows glazing) in the summer and winter thermal performance of this building. Subsequently, based on the cooling and heating seasons thermal performance, an optimum building envelope and operational solution is specified for average Csb climate conditions. Finally, design guidance is provided for the specification of building components and the operation of the building for the range of climatic conditions within the Csb climatic region.

This paper presents an equivalent elastic model where each bi-linear spring is replaced by two equivalent elastic springs using an energy formulation and in the context of a post-buckling stability analysis. Such a model yields analytical solutions for the evaluation of the behaviour of steel joints under compressive forces, combined axial force and bending moment, which enables the reproduction of their full non-linear behaviour. The resulting formulation is applied to a simple beam-to-column welded connection initially loaded in pure compression. Subsequent loading of the joint in combined bending and various levels of axial force clearly shows the reduction in moment capacity.

The possibility of having, in parts 1-1 and 1-2 of Eurocode 3, the same approach for the design of beam-columns and for lateral-torsional buckling, was investigated by the authors in previous papers using a numerical approach, where it was concluded that those assumptions could be made.In the present paper, a new approach for lateral-torsional buckling has been used with the formulae for the design of beam-columns at elevated temperature based on prEN 1993-1-1 combined with the formulae from prEN 1993-1-2. In both cases the results obtained are much better than the current design expressions, when compared with those obtained in the numerical calculations.