Study On Seismic Behavior Of The Frame Consisting Of PEC Columns (Weak Axis) And Steel Beams With Post-tensioned Friction Damped Connection

The self-centering structures have solved the problems of excessive residual deformation after earthquake,and structures cost less to repair after earthquakes.The post-tensioning(PT)strands are added to the main part of the self-centering structure with energy dissipation devices to achieve the purpose of self-reset and dissipation of energy in the earthquake.The research group developed an innovative PEC column-steel beam joint with post-tensioned friction damped connection based on the research of self-centering structure and the PEC proposed by research group.Under the seismic action of the design target,the connection energy dissipation is dominated by the friction energy dissipation.After the seismic load exceeds the design target,the main components of the structure further play a role,while avoiding excessive safety redundancy.Therefore,the partially self-centering connection form has a broader application field and theoretical research value.Results showed that the connection has excellent self-centering function and energy-dissipation ability.In order to study the seismic performance of PEC column-steel beam composite frame with Post-tensioned Friction Damped Connection.A two-story and one bay PEC column(Weak Axis)-steel beam composite frame which the bottom of the column is hinged with Post-tensioned Friction Damped Connection were designed to simulate its hysteretic behavior under quasi-static cyclic lateral loading.According to the phenomena and arrangement of simulated data,the force-transfer mechanism,energy-dissipation capacity,self-centering function,bearing capacity and joint area force-transfer mechanism of the specimen were analyzed.The results show that the lateral stiffness of second storey is greater than the lateral stiffness of first storey with columns bottom hinged,the process of the first storey structure is faster than that of the upper structure,and the storey reset well;The bearing capacity and stiffness of the simulated specimen are greater than the actual specimen,while the load-carrying curve of the specimen is consistent with that of the simulated specimen;Compared with hinged specimens,the specimens with fixed column bottom have higher bearing capacity and lateral stiffness;The inner and outer arrangement of bolts on the flange of the T-stubs part of the frame structure can prevent the inner side of the t-stubs part from warping deformation,so as to ensure the development of the structural stress process successfully;For buildings with different performance requirements,the force process of the structure can be controlled by changing the size of the long round holes on the T-stubs parts;Axial force accelerates the force process in PEC column and has little influence on the seismic performance of the structure;when the story drift angles arrive at the limit of story drift angle 0.02 rad set for moderate earthquakes,the residual rot of specimen was only 0.0026rad;Before the story drift angles arrive at 0.03 rad,the energy dissipation of the structure is basically provided by the connections;when the story drift angles arrive at the limit of story drift angle 0.035 rad set for strong earthquakes,the residual rot of specimen was only 0.008 rad,indicating that the frame possesses good self-centering function;when the story drift angles arrive at 0.04 rad,the bearing capacity of the structure did not decrease;The composite frame has good self-centering function,energy dissipation ability and collapse resistance;Main components of the specimen play a further role when the structure enters the pressure-bearing mode.