新型PEC柱–钢梁通长预拉杆摩擦耗能自复位层间抗震模拟

Numerical Simulation on Seismic Performance of Interstory Substructure of Innovative PEC Column-Steel Beam with Full-Length Post-Tensioned Bar and Friction Damped Connection

为了研究新型PEC柱–钢梁摩擦耗能自复位组合框架的抗震性能,以新型PEC柱–钢梁通长预拉杆摩擦耗能自复位中间层子结构试验试件为基本试件,考虑预拉杆预紧力、实际工程T型件对穿螺栓布置方式、T型件摩擦孔长度等设计参数,采用数值分析软件ABAQUS建立5个框架模型水平低周往复荷载下倒塌机理的数值模拟。基于试件整体、层间和节点滞回曲线、整体和节点残余转角图、节点处受力模式应力云图对试件的耗能承载能力和自复位功效进行分析。结果显示:采用摩擦耗能T形件的新型PEC柱–钢梁通长预拉杆自复位层间框架结构能较好满足自复位功效和耗散地震能能力的需求;摩擦T形件翼缘单边对穿螺栓的T形件未布置螺栓的翼缘面外撬拔面外变形明显,延缓了T形件摩擦滑移耗能能力的发挥;增大预拉杆预紧力造成摩擦滑移滞后,但改善了自复位功效;采用T形件翼缘双边对称螺栓布置可显著提高试件承载能力以及节点转动刚度;减小摩擦长圆孔尺寸,试件摩擦滑移耗能能力降低,钢梁端进进入屈服耗能加快,削弱了自复位效果;所有试件模拟加载至层间侧移角0.035 rad时,其残余转角均满足自复位结构节点转角限值小于0.005 rad的要求,甚至加载至层间侧移角0.05 rad时,残余侧移角未超过0.01 rad,即摩擦耗能T形件自复位连接PEC柱组合框架中间层试件具有良好的自复位功效和抗倒塌能力。

To investigate seismic performance of PEC column-steel beam composite frame with self-centering friction energy-dissipation connection, the test specimen of inter-story substructure of PEC column composite frame with full-length post-tensioned bar and friction energy-dissipation connection was selected as base specimen, several design parameters as pre-stress of post-tensioned bar, layout of high-strength penetrating bolts, the friction slot hole size were considered to design 5 specimens by the finite element software ABAQUS to simulate its seismic behavior under lateral cyclic reversed load. Self-centering function and energy-dissipation capacity of the specimens were analyzed based on the global and interstory hysteretic curves and Mises stress distribution of the specimens. The results indicated that interstory substructure of innovative PEC column-steel beam composite frame with full-length post-tensioned bar and friction energy-dissipation connection processes superior self-centering function and earthquake energy-dissipation capacity;layout of pre-tension penetrating bolts in one side of T-stub lead to out of plane deformation resulted from flange prying of T stud and delay the friction energy dissipation. Increasing the pretension force can delay the friction energy dissipation;however, the self-centre function was improved. The layout of pre-tension penetrating bolts in the two side of T stud can enhance bearing capacity and rotational stiffness observably. Shortening of frictional slot holes size reduce the friction energy dissipation, increase the energy dissipation of the beam yielding and reduce the self-centre function;when loading to inter-story drift 0.035 rad, the residual drift angle of all specimens were less than 0.005 rad, even loading to inter-story drift 0.05 rad, the residual drift angle of all specimen was less than 0.01 rad. Correspondingly innovative PEC column-steel beam self-centering composite frame with T-stud energy-dissipation connection indicates superior self-centering function and collapse-prevention capacity.