The design in case of fire is important for safe and economic steel constructions. Fire events in building can lead to enormous consequences for both owner, user and for society in general. This includes consequences for people and the environment as well as cultural, material and economical losses. In addition to a suitable design, it requires a good knowledge of the basic structural behavior of steel structures in case of fire and safer, more economical and at the same time easy to use verification methods, especially in case of stability failure of H-, I- and hollow sections at elevated temperatures. Design methods appropriate to these criteria, taking account of flexural buckling and lateral torsional buckling of steel member, are particularly important for the safe and economical fire design of steel structures.

The aim of this research project is to develop a consistent verification method for the design of steel member in compression and biaxial bending at elevated temperatures. The existing verification method is evolved on basis of numerical simulations and experimental results from literature and adjusted to verification methods at ambient temperatures. In addition, the scientific basis for expanding the scope of the verification method for high-strength steels is worked out.