消能摇摆钢桁架框架结构抗震性能

Seismic Behavior of Rocking-Truss-Frame with Dampers

摘要:

为研究消能摇摆钢桁架框架结构的抗震性能，使用OpenSees有限元软件对框架结构、支撑框架结构、摇摆钢桁架框架结构、消能摇摆钢桁架框架结构进行模态分析、静力弹塑性分析和动力弹塑性分析，讨论了4种结构的刚度特征、动力响应及损伤分布.此外，建立4种具有不同柱脚形式和阻尼器类型的对比结构，用以研究柱脚形式和阻尼器类型对于结构抗震性能的影响.研究表明，消能摇摆钢桁架框架结构具有良好的抗震性能；位移型阻尼器能够提高结构刚度和承载力、减震性能更优越，速度型阻尼器可以降低地震作用；底层框架柱脚采用铰接，可以降低地震作用，并减小底层框架柱的塑性损伤.

关键词:抗震性能; 摇摆钢桁架; 变形控制; 阻尼器; 柱脚形式

Abstract:

For the purpose of investigating the seismic behavior of rocking truss-frame with dampers, finite element models were established by software OpenSees, including frame structure, brace frame structure, rocking-truss-frame structure and rocking-truss-frame structure with displacement dampers. Based on the result of modal analysis, pushover analysis and time-history analysis, the characters of stiffness, dynamic response and damage were discussed. In order to illustrate influence of frame column root connection and dampers, four finite element models were established, which have different types of frame column roots and dampers. According to the analysis, rocking-truss-frame system has great seismic performance. Displacement dampers can improve structures stiffness and capacity, while velocity dampers can decrease story shear force. Pin-supported column roots are helpful to decreasing dynamic response and plastic damage of first floor columns.

Key words:seismic behavior; rocking steel truss; deformation control; damper; column root