دانلود رایگان مقاله انگلیسی عملکرد مبتنی بر طراحی لرزه ای قاب های خمشی خرپای زیگزاگ با دامپر اصطکاک - الزویر 2017

ABSTRACT

In this study performance-based seismic design procedure for staggered truss frames with friction dampers in the vierendeel panels was developed and their seismic performance was evaluated. To this end 6- and 12-story analysis model structures with friction dampers were designed using the capacity design procedure. For comparison the same structures without dampers were designed following the strength based approach specified in the ASCE 7–13, and the seismic performances of all model structures were compared. Fragility analyses were carried out to evaluate the seismic safety of the model structures and to validate the response modification factor used for seismic design. Analysis results showed that the capacity design method leaded to the formation of plastic hinges concentrated at vierendeel panels. It was also observed that the substitution of rotational friction dampers at the location of plastic hinges resulted in enhanced ductility and reduced probability of failure when the structures were subjected to design level seismic load.

6. Conclusions

In this study the seismic performance of staggered truss system structures with friction dampers in the vierendeel panels was evaluated. To this end 6- and 12-story structures with friction dampers were designed based on the capacity design procedure. For comparison the same structures without dampers were designed following the strength based approach specified in the ASCE 7-13, and the seismic performances of all model structures were compared. Fragility analyses were carried out to evaluate the seismic safety of the model structures and to validate the response modification factor used for seismic design.

According to the analysis results the plastic design method combined with the capacity design approach leaded to the formation of plastic hinges mainly at vierendeel panels when subjected to a seismic load. It was observed that the substitution of rotational friction dampers at the location of plastic hinges resulted in reduced overall strength but enhanced ductility and reduced probability of failure when the structures were subjected to design level seismic load. The application of the FEMA P695 process showed that the failure probabilities of the model structures designed using R=3 were small enough to ensure safety against MCE level earthquakes. However the same structures designed with R=6 failed to satisfy the safety requirement when designed following code-based procedure without friction dampers. Even in this case the seismic safety turned out to be enhanced to the level of safety when friction dampers were used in the chord members of the vierendeel panels.