Seismic design of plane steel frames using advanced methods of analysis

A rational and efficient seismic design methodology for plane steel frames using advanced methods of analysis in the framework of Eurocodes 8 and 3 is presented. This design methodology employs an advanced finite-element method of analysis that takes into account geometrical and material nonlinearities and member and frame imperfections. Seismic loads and resistances (strengths) are computed according to Eurocodes 8 and 3, respectively. The inelastic dynamic method in the time domain is employed with accelerograms taken from real earthquakes scaled so as to be compatible with the elastic design spectrum of Eurocode 8. The design procedure starts with assumed member sections, continues with the drifts, damage, plastic rotation and plastic hinge pattern checks for the damage, the ultimate and the serviceable limit states 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 through the interaction equations of Eurocode 3 or the usage of the conservative and crude q-factor suggested in Eurocode 8 are not required. Two numerical examples dealing with the design of one bay and four storey and two bay and seven storey moment resisting frames are presented to illustrate the method and demonstrate its advantages.