L-CFST柱-钢梁中节点抗震性能试验和有限元分析

Seismic Performance Test and Finite Element Analysis of Interior Joint in L-CFST Column and Steel Beam Frames

基于高层L形钢管混凝土组合异形柱(L-CFST柱)住宅结构体系,对两侧连接形式不同的中节点试件进行抗震性能研究.首先,对2个轴压比不同的足尺节点试件进行往复加载试验,对试件的破坏形态、滞回曲线、骨架曲线、延性系数、耗能能力及应变分布等进行对比分析.结果表明:试验的破坏主要发生在扩翼缘式端板连接处端板的鼓曲和拉裂,钢梁翼缘连接板圆弧过渡处的局部屈曲及开裂等,外肋环板式连接只出现了竖向肋板端部处钢梁翼缘连接板的轻微开裂.扩翼缘式端板连接与外肋环板式连接的刚度接近,但承载力相差较大.通过建立三维非线性有限元模型,并与试验结果进行对比分析,验证了有限元模型的准确性,并对影响扩翼缘式端板连接承载力的4种因素进行了参数化分析.

Based on the residential structure system with high-rise L-shaped column composed of concrete-filled steel tubes(L-CFST column),the seismic performance of the interior joint specimens with different side connections was studied.The low-frequency cyclic loading tests were carried out on two full-scale specimens with different axial compression ratios,and the failure modes,hysteretic curves,skeleton curves,ductility coefficient,energy dissipation capacity and strain distribution of the specimens were compared and analyzed.The test results showed that the damage mainly occurred in the widened beam flange connection with end plates,including the buckling and cracking in the end plates and the local buckling and cracking in the curved corners of the beam flange connecting plates.However,only slight cracking occurred in the beam flange connecting plate at the end of vertical stiffeners in the vertical stiffener connection.The initial stiffness of the two types of connections was close,but the peak force was quite different.A three-dimensional nonlinear finite element model was established and compared with the experimental results,and the accuracy of the finite element model was verified.The parametric analysis of four factors that influence the bearing capacity was carried out.