钢管柱-剪力墙转换节点抗震性能的数值模拟

Numerical Analysis on Seismic Behavior of Steel Tubular Column-Shear Wall Transformation Nodes

为探讨轴向压力和低周往复荷载双重作用下,不同高度混凝土内填充的钢管柱的抗震性能,将有限元模型和试验结果进行比较,验证了有限元建模方法的准确性。基于已验证的有限元模型,围绕滞回曲线、骨架曲线、初始刚度和刚度退化曲线、能量耗能能力,探究核心混凝土高度、核心混凝土强度、外钢管的钢材强度、轴压比和构件的径厚比等参数对钢管柱抗震性能的影响。结果表明:1)核心混凝土的高度对钢管柱的抗震性能影响最为显著,填充混凝土高度较低的钢管柱由于混凝土填充量较小,其峰值荷载和失效位移较低;随着混凝土高度从1/4钢管柱高度增加到1/2钢管柱高度,峰值荷载和失效位移显著提高,循环加载总次数也明显增加,因此,在设计钢管柱时,应特别关注混凝土的填充高度,以确保足够的抗震性能;2)核心混凝土和钢材的强度对抗震性能的影响较小,高强度混凝土和钢材不会显著增加钢管柱的初始刚度,即在一定范围内,可以选择不同的混凝土和钢材材料,而不会对抗震性能产生重大影响,但实际工程中,仍然需要根据具体情况选择合适的材料以满足强度和刚度要求;3)轴压比和构件径厚比的增加可以在一定程度上提高抗震性能,特别是对耗能能力有积极影响,增加轴压比可以提高钢管柱的承载能力,而增加构件的径厚比可以增加钢管柱的刚度,从而增加其抗震性能,因此,在实际设计中,需要综合考虑这两个参数以优化钢管柱的抗震性能。

This study investigates the seismic performance of steel columns with different heights of concrete core fill under the combined action of axial compression and low-cycle reversed loading.The comparison between finite element modeling and experimental results is employed to validate the accuracy of finite element modeling method.The fundamental parameters studied in the finite element model include the height of the core concrete,core concrete strength,steel material strength of the outer steel tube,axial load ratio,and the diameter-to-thickness ratio of the members,among others,all of which have a significant impact on the seismic performance of steel columns.The finite element analysis primarily focuses on hysteresis loops,skeleton curves,initial stiffness,stiffness degradation curves,and energy dissipation capacity.The following findings were obtained:Firstly,the height of the core concrete significantly influences the seismic performance of steel columns.Steel columns with lower concrete fill heights exhibit lower peak loads and failure displacements due to the smaller volume of concrete fill.As the concrete height increases from 0.25 times the column height to 0.5 times the column height,both peak loads and failure displacements increase significantly,along with a notable increase in the total number of cyclic loading cycles.This underscores the importance of considering concrete filling height in the design of steel columns to ensure adequate seismic performance.Secondly,the influence of the strength of the core concrete and steel material on seismic performance is relatively minor.High-strength concrete and steel do not significantly increase the initial stiffness of steel columns.This suggests that within a certain range,different concrete and steel materials can be chosen without a substantial impact on seismic performance.However,practical engineering still requires the selection of appropriate materials based on specific strength and stiffness requirements. Finally, an increase in the axial load ratio and the diameter-to-thickness ratio of members can enhance seismic performance to some extent, particularly in terms of energy dissipation capacity. Increasing the axial load ratio improves the load-carrying capacity of steel columns, while increasing the diameter-to-thickness ratio enhances their stiffness, thereby improving their seismic performance. Therefore, practical design considerations should comprehensively take these two parameters into account to optimize the seismic performance of steel columns.