ATCFSST-SCB中柱节点M-θ骨架曲线影响因素分析

摘要

In order to analyze how the moment (M)-rotation (θ) skeleton curves of outer annular-stiffener type concrete filled square steel tube-steel castellated beam (ATCFSST-SCB) joints are influenced by different parameters,25 such interior joints were designed.Their loading-bearing process was simulated by using finite element software ABAQUS,and before simulation,the simulating method was verified by previous relevant test result.The M-θ skeleton curves of these joints were also extracted.The yield flexural capacity,the ultimate flexural capacity and the initial stiffness of each joint were also calculated.By analyzing the above results,it can be concluded:with the increasing of axial compression ratio or steel yield strength,the yield flexural capacity,the ultimate flexural capacity and the initial stiffness of the joints increases,yet they have small effect on the initial stiffness;with the increase of beam to column linear stiffness ratio,the yield flexural capacity,the ultimate flexural capacity and the initial stiffness of the joints increases,and especially the initial stiffness increases much large;with the increase of stiffener ring width,the yield flexural capacity and the ultimate flexural capacity increases,yet the initial stiffness increases at first and then decreases;with the increase of steel ratio,the yield flexural and the initial stiffness increases largely,yet the ultimate flexural capacity increases small;with the increase of opening rate,the yield flexural capacity,the ultimate flexural capacity and the initial stiffness decreases,and the decreasing extent is small if the opening rate is not very large;with the increase of hole spacing and the distance of the first hole border in SCB to the column border,the yield flexural capacity and the ultimate flexural capacity of the joints increases,but if these two parameters increase or decrease too much,the initial stiffness would be decreased.%为分析不同因素对外加强环式方钢管混凝土柱-钢蜂窝梁节点弯矩(M)-转角(θ)骨架曲线的影响,设计了25个不同参数的该种节点,采用有限元软件ABAQUS模拟了这些节点在低周往复荷载作用下的受力过程,模拟前采用已有试验数据对模拟方法进行了验证.提取了各节点的M-θ骨架曲线,并计算了各节点的抗弯承载力、极限抗弯承载力和初始刚度.通过对比分析,得出如下结论:轴压比、钢材屈服强度增加,节点的抗弯和极限抗弯承载力明显提高,而初始刚度受其影响较小;梁柱线刚度比增加,节点的抗弯、极限抗弯承载力、初始刚度增加,且初始刚度增加较大;加强环板宽度增加,节点抗弯、极限抗弯承载力增大,初始刚度先增加后减小;含钢率增加,节点抗弯承载力、初始刚度明显增加,极限抗弯承载力小幅增加;开孔率增加,节点抗弯、极限抗弯承载力、初始刚度降低,且开孔率不是很大时,三者降低较小,而孔间距、距离的增加,均会提高节点的抗弯、极限抗弯承载力,但二者过大或过小均会引起节点的初始刚度降低.