罕遇地震作用下BRB加固对结构抗震性能的影响

Influences of Different BRB Arrangements on Seismic Performance of Buckling Restrained Braced Structures

屈曲约束支撑是一种新型耗能减震构件,质量轻、施工速度快、对原结构影响小,能够保护主体结构在罕遇地震作用下不屈服或者不严重破坏,在结构加固中应用广泛。为了探讨罕遇地震作用下不同BRB布置对屈曲约束支撑结构抗震性能影响,对5种不同BRB布置方式的框架进行了罕遇地震下的动力时程分析,得到了结构的层间位移角、顶层监测点位移、顶层监测点加速度、基底剪力和屈曲约束支撑滞回耗能。研究结果表明:在结构端部和中部设置屈曲约束支撑的受力性能和抗震性能优于原结构和其他BRB布置方式的结构;在罕遇地震作用下,既有混凝土框架结构中的屈曲约束支撑处于塑性阶段,进入屈服耗能时期,并向结构提供侧向刚度。

Buckling restrained brace is a new type of energy-dissipation and shock-absorbing member with light weight,fast construction speed and little impact on the original structure.It can protect the main structure from yielding or serious damage under rare earthquake,and is widely used in structural reinforcement.To investigate the influence of different BRB arrangements on the seismic performance of BRB structures,the dynamic time-history analysis of frames with five different BRB arrangements under rare earthquakes was carried out.Under the action of EIcentro wave,dynamic time-history analysis of frames with five different BRB arrangements under rare earthquakes was conducted obtaining the data of interlayer displacement angle,displacement of top monitoring point,acceleration of top monitoring point,base shear and hysteretic energy.The results show that the mechanical and seismic performance of structures with buckling restraint braces at the ends and middle of the structure is superior to that of the original structure and other BRB arrangements and that under the rare earthquake,the buckling restraint brace in the existing concrete frame structure in the plastic stage can enter the yield energy dissipation period and provide lateral stiffness for the structure.