变摩擦自复位支撑钢框架的抗震性能影响因素研究

Influence factor analysis on seismic performance of avariable friction damper self-centering braced steel frame

为提升支撑钢框架在大震下的抗震性能,提出一种随加载位移改变摩擦力及刚度的变摩擦自复位支撑(variable friction damper-self-centering brace,VFD-SCB)。在对VFD-SCB变摩擦工作机理和力学性能分析的基础上,利用OpenSees软件对其滞回模型进行二次开发,并将计算结果与试验结果进行对比,验证了模型的有效性。通过建立VFD-SCB框架和传统抗弯钢框架(moment-resisting frame,MRF),研究了支撑关键参数对VFD-SCB框架抗震性能的影响规律。参数分析结果表明:相比传统抗弯钢框架,VFD-SCB框架有效减小了结构最大位移角及残余位移角,使结构沿层高变形更均匀;VFD-SCB第一刚度、第三刚度、碟簧预紧力的增大及二次启动位移的减小,结构的层间位移角均减小;设计中需全面考虑支撑和框架参数以提升结构的抗震性能。

To improve the seismic performances of steel braced frames under maximum considered earthquake,a variable friction damper-self-centering brace(VFD-SCB)that can provide variable friction force and stiffness with different loading displacements was proposed.Based on the working mechanism and mechanical property of variable friction,the hysteretic behavior of VFD-SCB was developed in OpenSees software.The calculation results were compared with theoretical and experimental results,verifying the reliability of the developed model.Though the analysis of VFD-SCB and traditional moment-resisting frame(MRF),the key parameters were considered to evaluate their influences on seismic performance.The parametric analysis shows that compared to the MRF,the VFD-SCB frame effectively reduces the maximum and residual drift with uniform deformation along the story height.With the increases of initial stiffness,third stiffness,prestressed force of disc springs,and the decreases of the second activation displacement,the drifts of the frame reduce after comprehensively considering the brace and frame parameters.