چكيده به لاتين
The main basis of modern structures design,is using of material nonlinear capacity to resist against earthquake force.Although this problem reduces weight of structure and makes the design more economical,but especially in the large earthquakes, causing structure entrance to nonlinear area,reducing the strength and causing great displacement that after the earthquake is not reversible.Need operational use of very important buildings even after the earthquake,has caused several systems presented in recent years to solve this problem.
Self-Centering systems are the newest systems that using its own mechanism,can return the structure to its initial condition after earthquake.in this study,one of the latest of these systems called Self-Centering Buckling Restrained Brace was introduced.At the same time,this brace has both high energy absorption characteristic dependent on Buckling Restrained Brace and removing residual strain even at large deformations with Shape Memory Alloy.Moreover this system can be constructed easier than similar bracing systems.
In this study,with the help of open source and powerful OpenSees program,this brace was modeled and after validating by experimental results,the effective factors on its self-centering performance was introduced.In the next step a residential structure with high relative seismic risk and soil type II was modeled and ductility capacity was evaluated.A total of 40 models was made and analysed in the program.Results of this study showed that the area of SMA relative to the area of steel core of BRB has the greatest impact on the behavior of brace and the ratio Asma/Abrb=5 has the proper performance.Moreover ,ductility of this system in all models was more than convetional systems and if the brace properly be desiged,it can properly dissipate energy and remove plastic displacement.
Keywords: Self-Centering system,Residual strain,Shape Memory Alloy,Bulcking Restrained Brace
