Ductility Demand Models
In recent years many researchers have tried to find engineering procedures to do this task but each had some limitations. Studies have shown that Push Over Analysis is limited to low to medium rise buildings and is not recommended for high rise or flexible structures in which higher mode effects are not negligible and may govern the dynamic response . Other existing methods such as the Capacity Spectrum Method and the N2 Method have similar limitations. In the first part of this section, simple plastic models for the story or local ductility of braced steel building with concentric and eccentric bracing systems have been proposed. In the second part, various functions for ductility demand distribution over the height of the structure have been introduced and then they have been verified by comparing to dynamic analysis results through various numerical examples.