形状记忆合金自复位钢框架节点抗震性能数值模拟及参数分析

Numerical simulation and parameter analysis of seismic performance of self-centering steel frame joints with shape memory alloy tendons

基于ABAQUS二次开发平台,编制了超弹性形状记忆合金(SMA)一维分段线性本构模型子程序,并将其嵌入到ABAQUS材料库中,通过实例分析,验证了子程序的正确性。基于ABAQUS平台,建立了自复位钢框架节点分析模型,分析了钢框架节点在低周往复荷载作用下的滞回性能、骨架曲线、刚度退化、耗能能力及残余变形等抗震性能,并和普通钢节点进行了对比。对SMA自复位钢框架节点进行了参数分析,考虑了SMA筋预应力水平、位置、配置量及角钢厚度对自复位钢框架节点抗震性能的影响。分析结果表明:与普通钢框架节点相比,SMA自复位钢框架节点承载力大大增加,卸载后有效地消除了残余变形,具有良好的自复位效果;SMA预应力大小、竖向间距、配置量和角钢厚度等参数对新型钢框架节点的承载能力和复位性能均有明显的影响。

Based on the FEM software ABAQUS, a subroutine program describing the one-dimensional piecewise linear constitutive model of the superelastic shape memory alloy is developed. With the open subroutine connector, the developed program is inserted into the material library of ABAQUS. With the numerical analysis of a real steel frame joint, the effectiveness of the developed subroutine program is also verified. Based on software ABAQUS, a numerical model of the self-centering steel joint （SJ） is built. And the seismic performances of the self-centering steel frame joint under the persudo-static cyclic loading are carried out. The cyclic properties, such as hysteretic behavior, skeleton curves, stiffness degradation, residual deformation and energy dissipation, are analyzed and compared with the common steel joint （CJ）. The effect of main parameters on the mechanical properties of SJ are analyzed, including the SMA＇ s pre-stress, SMA tendons＇ position, SMA tendons number as well as the thickness of steel angle. The results show that the SMA steel frame joint has good hysteretic properties, while very small re- sidual deformation, exhibiting satisfactory energy dissipation and self-centering capacities. Moreover, the SMA parameters and the thickness of steel angle have significant effect on the seismic performance of the SMA steel frame joints.