巨震作用下非线性黏滞阻尼耗能RC框架结构抗倒塌分析

Collapse-resistant capacity of RC frame structure of nonlinear viscous damping dissipates energy subjected to mega earthquakes

基于SAP2000软件,对设置非线性黏滞阻尼耗能减震及传统抗震的十层RC框架结构进行巨震作用下非线性动力时程分析及结构抗倒塌易损性分析,研究巨震作用下结构响应、阻尼耗能、抗倒塌安全储备及结构塑性铰分布等。根据上述两种框架结构巨震作用的弹塑性反应,分析非线性黏滞阻尼器耗能,并采用基于IDA的结构抗倒塌易损性分析方法,按照对数正态分布拟合结构倒塌易损性曲线,从而分析上述两种框架结构的抗倒塌安全储备及塑性铰分布。结果表明,巨震作用下非线性黏滞阻尼能有效耗散地震能量,提高框架结构的减震能力及抗倒塌安全储备,具有良好的抗倒塌性能。

Elastoplastic dynamic time-history analysis and collapse fragility analysis are carried out for a tenstorey reinforced concrete frame structure with and without nonlinear viscous damping dampers based on SAP2000 software,from which the structural response,damping energy dissipation,safety margins against collapse and the plastic hinge distribution of the structures subjected to the mega earthquakes are studied respectively. According to the structural elastoplastic response of the above two types of frame structures,the energy dissipation of the nonlinear viscous damper is analyzed. Besides,with collapse fragility analysis based on an incremental dynamic analysis(IDA),the collapse fragility curves of the structures are fitted according to the logarithmic normal distribution. From this,the safety margins against collapse and the plastic hinge distributions of the above two types of frame structures are researched. The results show that the nonlinear viscous damping can effectively dissipate seismic energy under the mega earthquakes,improve the structural damping effect and the safety margins against collapse,and have good collapse-resistant capacities.