Use of advanced methods of analysis in seismic design of moment resisting steel frames

A rational and efficient seismic design methodology for moment resisting steel frames using advanced methods of analysis in the framework of EC8 and 3 is presented. This design methodology employs an advanced time domain finite element method of analysis that takes into account geometrical and material non-linearities and member and frame imperfections. Seismic input is in the form of scaled real earthquake accelerograms so as to be spectrum or intensity compatible with EC8, while resistances (strengths) are computed according to EC3. The design procedure starts with assumed member sections, continues with the ultimate load carrying capacity check, the serviceability check, the damage and the ductility check and ends with the adjustment of member sizes. Thus it can sufficiently capture the limit states of displacements, strength, stability and damage of the structure and its individual members so that separate member capacity checks or the usage of the conservative and crude q-factor suggested in EC8 are not required. Two examples involving one plane and one space steel frame are presented and discussed.