Buildings are designed per building code regulations, aptly termed Prescriptive Based Design. It is a methodology based upon meeting all of the specific requirements of the code.
In prescriptive based design, the normal engineering analysis practice is to assume linear-elastic behavior for structural members, which fails to reliably account for redistribution of forces due to member nonlinear behavior and dissipation of energy due to material yielding. Because of this, considerable damage has been observed and life safety goals was not achieved from major earthquakes in recent decades in residential and commercial buildings. Safety is understood as the structures ability to deform in the inelastic range but no collapsed is allowed.
During high seismic excitation, the building generally responds well beyond its elastic and linear capacity. There are two inelastic nonlinear options available for assessing the performance of a structure subjected to earthquake load; namely Pushover Analysis and Inelastic Nonlinear Time History Analysis. These two methods of analyses are used in Performance Based Design. It is a methodology using advanced engineering tools and methods to provide solutions to complex life safety problems in order to achieved life safety goals.
The purpose of this presentation is to explain the procedure in performing Inelastic Nonlinear Analysis using the professional software XTRACT v3.0.8 and PERFORM-3D v4.0.3, to evaluate the performance of multi-storey buildings (designed by traditional linear static and linear dynamic load procedures) when subjected to earthquake ground motion.