斜交钢−混凝土组合空间节点抗震性能试验研究

Experimental study on seismic performance of skew steel−concrete composite spatial joints

按照1꞉4缩尺完成1个斜交钢−混凝土组合空间梁柱节点,以柱端加载方式对本试件开展水平低周循环荷载试验。主要研究节点核心区的受力特征、破坏形态和抗震性能。利用ABAQUS有限元软件模拟试验,在模拟结果与试验结果对应较好的前提下,建立18个有限元模型分析轴压比、柱型钢腹板厚度及型钢翼缘厚度3种参数对节点承载力的影响。研究结果表明:在加载后期,试件的节点核心区产生明显的剪切变形,并伴随扭转现象,反映了节点产生平扭耦联的空间作用特点;试件的滞回性能、承载力、刚度和耗能能力较强,反映了此节点具有良好的抗震性能;且节点的极限位移角为1/25,满足规范规定1/50的限值要求;适当增大轴压比对提高承载力有利;在低配钢率下,优先增加翼缘厚度对提高承载力更有效;在高配钢率下,优先增加腹板厚度对提高承载力更有效。

One skew steel-concrete composite spatial beam-column joints was completed on the 1꞉4 scale,and the horizontal low cyclic load test was carried out on this specimen by the method of column end loading.The stress characteristics,failure mode and seismic performance of the core area of the joints were mainly studied.ABAQUS finite element software was used to simulate the test.On the premise of good correspondence between the simulation results and the test results,18 finite element models were established to analyze the influence of three parameters on the bearing capacity of the joints,namely,the axial compression ratio,web thickness and flange thickness of column steel.The results show that in the later stage of loading,obvious shear deformation occurs in the core area of the joints of the specimen,accompanied by torsion,which reflects the characteristics of the spatial effect of the horizontal-torsional coupling of the joints;the hysteretic performance,bearing capacity,stiffness and energy dissipation capacity of the specimen are good,which reflects that the joints has good seismic performance;the ultimate displacement angle of the joints is 1/25,which meets the limit requirement of 1/50 specified in the specification.Increasing the axial compression ratio properly is beneficial to improve the bearing capacity;at the low steel ratio,preferentially increasing the flange thickness is more effective in improving the bearing capacity;at the high steel ratio,preferentially increasing the web thickness is more effective in improving the bearing capacity.