Study On The Performance Based Seismic Design Of Portal Frame Light Steel Structures With Different Joint Forms

Earthquakes have significant effects on the modern society. And the society and the public have different level of demands for the seismic performance of structures. In the 21st century, the main trend of seismic design is Performance Based Seismic Design (PBSD), in which the performance of a structure is guaranteed to satisfy different demands of the owner, the user or the society under different levels of earthquakes. Meanwhile, the main objective of traditional seismic design is life safety, and multiple performance objectives are not satisfactorily included. Therefore, the study on the performance based seismic design of portal frames are of great significance from both theoretical and practical point of views.First, the develop history and special features of portal frame light steel structures are introduced, as well as different seismic design concepts. Second, evolution of the structural seismic design theory is summarized; common seismic analysis methods for portal frame light steel structures are listed; and the globally prevailing performance based seismic design theory is introduced in detail. Finally, a systematic introduction of the seismic performance portal frame light steel structures is presented; pushover analyses are conducted for 36 models; seismic performances under 3 different levels of earthquakes are evaluated, by using the capacity spectrum method; and the effects of different forms of beam-column joints and foot joints on the structural seismic performance in portal frames with different heights and spans are summarized from the analysis results.