钢筋混凝土框架外设自复位构件加固抗震性能研究

STUDY ON SEISMIC PERFORMANCE OF SELF-CENTERING MEMBER REINFORCED FRAME BASED ON FINITE ELEMENT

外设自复位构件加固框架的方法是先对框架梁柱采用增大截面法进行加固,后在加固柱截面外侧,沿加固梁并排设置预制梁,预制梁内部张拉无粘结预应力筋,预拉力弹性拉紧作用降低框架震后残余变形率,并在节点设置耗能钢筋,降低节点动力响应。采用有限元分析软件对3榀缩尺试验模型进行拟静力加载,将模拟结果与试验结果对比,验证建模合理性,建立3组共7榀框架进行变参数模拟,考察框架抗震性能影响因素,研究表明,建模方法可较好模拟外设自复位框架的受力特征。预制梁可提高加固后框架承载力,耗能钢筋提高节点处耗能作用较显著,可显著降低框架震后残余变形率,提高加固后框架抗震性能。

The mechanical properties of the frame strengthened with external self-centering components are studied.The frame beam and column are strengthened by increasing the cross-section method.Then,on the outer side of the section of the strengthened column,prefabricated beams are arranged side by side along the strengthened beams.The unbonded prestressed tendons are tensioned inside the prefabricated beams.The elastic tensioning effect of the pretension reduces the residual deformation rate of the frame after the earthquake,and the energy dissipation steel bars are set at the joints to reduce the dynamic response of the joints.The finite element analysis software is used to carry out quasi-static loading on three scale test models.The simulation results are compared with the test results to verify the rationality of the modeling.Three groups of seven frames are established for variable parameter simulation to investigate the influencing factors of the seismic performance of the frame.The research shows that the modeling method in this paper can better simulate the mechanical characteristics of the external self-centering frame.At the same time,the precast beam can improve the bearing capacity of the reinforced frame,and the energy dissipation effect of the energy dissipation steel bar is more significant,which can significantly reduce the residual deformation rate of the frame after the earthquake and improve the seismic performance of the reinforced frame.