新型自复位钢桁架梁的受力机理及抗震性能

将预应力钢绞线与消能杆引入钢桁架梁，利用消能杆、预应力钢绞线分别来消耗构件的变形能、实现结构的自复位功能，从而有效减轻结构震后残余变形。理论推导了自复位钢桁架梁端截面对应于其恢复力骨架曲线关键特征点处的弯矩和刚度值；采用有限元分析软件OpenSees建立了钢桁架梁的分析模型，进行了单向和往复水平荷载下非线性分析。结果表明：对应关键点处的梁端弯矩和刚度的模拟值与理论值吻合较好，往复荷载作用下分析结果验证了该类钢桁架梁具有很好的自复位和耗能性能。

Analysis of stress mechanism and seismic behavior of a new self-centering steel truss beam

The post-tensioned steel strand and energy dissipation bars are used to a self-centering steel truss beam to dissipate energy and reduce effectively residual deformation of the structure, respectively. The theoretical value of moment capacity and stiffness at end of beam are deducted correspond to major points of its backbone of their hysteretic curve. The nonlinear mechanical properties of beam are analyzed by Open Sees. the simulation results such as moment and stiffness are very consistent with theoretical analysis results, thus the effectiveness of nonlinear analytical model is proved. The nonlinear analysis results show that the steel truss beam is capable of self-centering and energy dissipation under cyclic loading.