耗能梁长度对自复位Y型偏心支撑钢框架力学性能的影响

Effect of SMA Link Beam Length on the Mechanical Behavior of Self-Centering Y-Shape Eccentrically Braced Steel Frame

为研究形状记忆合金(Shape Memory Alloy,SMA)耗能梁长度对自复位Y型偏心支撑钢框架滞回性能及复位效果的影响,基于理论分析建立了剪切型SMA耗能梁最小长度的计算公式以及确保此类结构出现理想塑性机制的保障措施;并采用ANSYS建立了4个不同耗能梁长度的自复位Y型偏心支撑钢框架的精细化有限元模型,进行了滞回性能分析,对比了各算例的滞回性能、水平承载力、抗侧刚度、耗能能力、复位效果及SMA耗能梁腹板的应力分布.研究结果表明:耗能梁最小长度计算公式可确保耗能梁在超弹性范围内工作;理想塑性机制保障措施可提高结构复位效果;剪切型耗能梁较弯剪型水平承载力高、抗侧刚度大、耗能能力强、连接构造简单、材料利用率高;耗能梁类型对此类结构的复位效果影响不大.因此,耗能梁宜设计为剪切型,但不宜过短,需满足最小长度限值要求.

To investigate the influence of Shape Memory Alloy（SMA） link beam length on the hysteretic behavior and self-centering behavior of self-centering Y-shape eccentrically braced steel frame structure,the formula for calculating the minimum length of shear-type SMA link beam and guarantee measures for structural ideal plastic mechanism were derived via theoretical analysis.A total of four finite element models（FEM） of Y-shape eccentrically brace steel frame with different link beam lengths were constructed and analyzed under cyclic loads using ANSYS software. After comparing their hysteretic behavior,the lateral bearing capacity,lateral stiffness,energy dissipation and stress distribution located in SMA link beam web,it is found that the minimum length calculation formula of link beam can effectively control link beam to work within the super elastic range. The self-centering Y-shape eccentrically braced steel frame structure with ideal plastic mechanism can significantly improve the structural selfcentering behavior. The shear-type SMA link beam has some advantages,including of high lateral bearing capacity,large lateral stiffness,super energy dissipation capacity,and so on. The type of SMA link beam has not obvious influence on the self-centering behavior of Y-shape eccentrically braced steel frame structure. Therefore,the SMA link beam is suggested to design the shear-type,but it should not be too short,and must satisfy the minimum length limit.