Direct damage controlled seismic design of steel framed structures

PBD (SEAOC 1999) introduces a new framework in seismic design of structures by defining performance levels and objectives. Thus, three to five structural performance levels are defined and should be achieved for increasing levels of earthquake actions. These performance levels mainly describe the damage of a structure which is quantified through indices, such as the interstory drift ratio (IDR), or the member plastic rotations.