为研究摩擦耗能T形连接件部分自复位连接的抗震性能,考虑PEC柱布置方式,按1∶1.6缩尺比例设计制作2个新型PEC柱-钢梁中节点试件模型,并进行水平低周往复荷载试验。基于试验测试数据整理,对试件的滞回性能、承载能力、耗能能力、自复位功效和节点传力机理等进行分析。结果表明:摩擦耗能T形连接件部分自复位连接通过预拉杆和摩擦耗能T形连接件有效实现了"自复位功效与耗能能力有机统一"的性态设计目标;PEC柱布置方式决定其受力性能,且改变了节点梁柱刚度匹配,从而影响到连接形式受力性能的发展进程和试件损伤分布规律;对穿螺栓和预拉杆实现了节点域混凝土斜压带传力模式,相应降低了节点域腹板的抗剪性能要求;所有试件层间侧移角达到中震层间侧移角限值0.02rad之前,节点与连接基本无残余转角,而当层间侧移角超过大震层间侧移角限值0.035rad时,试件承载能力仍呈增大趋势、且对应节点与连接残余转角不超过0.01rad,即该连接形式具有良好的自复位功效和抗倒塌性能。
Two large-size interior joints of new crimping PEC column-steel beam with post-tensioned friction damped connection were tested under lateral low-cycle repeated loading,and the column layout as a design parameter was taken into consideration. From the tests,the load-rotation angle hysteretic curves were derived. Based on the test data and observation,the seismic behaviors of specimens,including the load-carrying capacity,energy-dissipation capacity,selfcentering function and force transfer mechanism of joint,were studied. The results show that pretensioning bars provide restoring force and self-centering function that reduce the potential of residual drift and alleviate structural damage process,while energy dissipation elements can be used to dissipate earthquake energy and reduce the structural response; PEC column layout governs the stiffness distribution of column-beam joints and affects the mechanical process of partial self-centering connection and the damage pattern of specimens; due to the setting of pretensioning penetration bolts and pretensioning bars,the force transfer mechanism of concrete equivalent strut in the panel zone is formed,which correspondingly reduces the demand on shear resistance of steel web; before the storey drift angles for all specimens arrive at the limit of storey drift angle 0. 02 rad set for moderate earthquakes,the residual rotation angle basically satisfies the limit of storey drift angle 0. 005 rad set for small earthquakes,and when the storey drift angles exceed the limit of storey drift angle 0. 035 rad set for strong earthquakes,the load-carrying capacity of specimen still has the increasing tendency and the corresponding unloading residual drift angles don't exceed 0. 015 rad,indicating that the connection type possesses good capacity of rotation,energy-dissipation capacity,self-centering function and collapse resistance.