New Directions in Structural Seismic Designs

The code stipulated seismic force requirements for buildings from the historical point of view are described first. This is followed by examples of the emerging criteria of inelastic seismic spectra for displacement ductility, and number of yield reversals as a function of building period and strength. Novel spatial representations of seismic input energy and hysteresis energy, interpreted as damage energy, are given next. The available structural resistance countering the imposed seismic demand is illustrated by the ductile behavior of steel moment resisting frames (MRFs) and eccentrically braced frames (EBFs). A discussion of a practical and versatile frictional energy dissipating connection is given at the end.