Seismic yield displacements of plane moment resisting and x-braced steel frames

Approximate formulae for the estimation of lateral displacements at first yielding of plane steel frames under seismic excitations are provided for use in a performance based seismic design and more particularly, in a direct displacement based seismic design of these structures. These formulae, which are functions of the geometrical and design properties of the frames, are derived on the basis of seismic response data obtained with the aid of extensive dynamic inelastic analyses involving 36 moment resisting and 36 x-braced plane steel frames with steel grade S235, S275 and S355 under 84 ordinary seismic ground motions. Comparison of the proposed formulae against other simpler existing formulae, reveals the higher accuracy of the proposed ones.

► Yield displacements under seismic excitations. ► Yield displacements for plane steel MRF. ► Yield displacements for plane steel XBF.