新型PEC柱-钢梁摩擦耗能部分自复位节点抗震性能数值模拟

Numerical Simulation on Seismic Performance of Innovative PEC Column-Steel Beam Interior Joint with Post-tensioned Friction Damped Connection

为研究采用预拉对穿螺栓的新型PEC柱-钢梁摩擦耗能型部分自复位连接中节点的抗震性能,考虑PEC轴压力、钢板组合截面布置(强/弱轴)、预拉杆预应力、加强型盖板厚度和预拉对穿螺栓设置方式等5个设计参数,利用有限元软件ABAQUS建立8个中节点模型试件并对其进行循环荷载下受力性能的数值模拟。根据模拟结果分析了连接的弯矩-转角关系、自复位功效、耗能能力、受力变形模式和节点传力机理。研究结果显示:PEC柱轴压力产生的二阶效应加快了自复位节点受力发展进程,但不影响自复位功效;组合柱布置方式通过改变梁柱刚度匹配影响连接部位力的分配模式,但不影响部分自复位节点受力机理;预拉杆预应力明显改变节点摩擦滑移耗能和自复位能力;预拉对穿螺栓的设置较好实现了节点区混凝土斜压带传力机理;采用实际工程作法的所有试件残余转角均不超过自复位节点最小转角限值0.005rad,且在达到设计预定的中震侧移角限值0.02rad后,结构主要受力构件梁开始进一步发挥力学性能,实现了自复位功效、耗能能力与结构安全冗余度有机统一的性能设计目标。

To investigate seismic performance PEC column fabricated with crimping thin-walled built-up section-steel beam interior joint with post-tensioned friction damped connection,the design parameters as axial compression,PEC column layout,prestress of prestressed bar,the thickness of reinforced cover plate and layout of pre-tensioned high-strength penetrating bolts were taken into consideration,the finite element software ABAQUS was adopted to build 8 mechanical models and further simulate their mechanical performances under lateral cyclic loading. Based on numerical simulation results,the specimens performance are analyzed,including moment-rotation relationship,self-centering function,energy-dissipation capacity,loading-deformation style and force-transferring mechanism. The research showed that second-order of PEC column axial compression fasten its mechanics process but not affected its self-centering function; PEC column layout altered load distribution but not its mechanism; value of prestressed bar is critical for selfcentering function and energy-dissipation capacity; the force-transfer mechanism of concrete equivalent strut in the panel zone was formed due to pre-tension penetrating bolts; all specimens from practical application exhibited various degrees of self-centering functions and sound energy-dissipation capacity as residual rotation all less than its limit 0. 005 rad,meanwhile the mechanical performance of steel beam was further utilized when rotation surpassed the predetermined design value of 0. 02 rad,correspondingly the performancebased design object of partial self-centering and energy-dissipation matched well with the safety redundancy.