初始几何缺陷对屈曲约束支撑低周疲劳性能的影响

Effect of initial geometric defects on low cycle fatigue performance of buckling-restrained brace

为探究屈曲约束支撑核心板的初始几何缺陷对其耗能性能及低周疲劳性能的影响,利用有限元分析软件ABAQUS搭建了装配式屈曲约束支撑模型,并将其核心板的屈曲模态作为初始几何缺陷引入到该模型中,分别对引入初始几何缺陷前后的2个模型进行了5组等幅加载试验,利用疲劳分析软件Fe﹣safe对2个屈曲约束支撑模型分别进行了疲劳寿命计算。结果表明:在核心板的初始几何缺陷影响下,屈曲约束支撑疲劳寿命的降低程度在3.5%到7.1%之间,累积塑性变形值的降低程度在0.7%到3.8%之间;此外,初始几何缺陷在一定程度上会增加屈曲约束支撑在循环荷载作用下的不稳定性,但是初始几何缺陷没有对其耗能性能及低周疲劳性能造成显著影响。

In order to investigate influence of initial geometric defects on the energy dissipation performance and low cycle fatigue performance of the buckling﹣restrained brace core plate,finite element analysis software ABAQUS was used to build the BRB model,the buckling modes of the core plate were introduced into the BRB model as initial geometric defects,the two models before and after the initial geometric defects introducing were subjected to five constant amplitude loading tests,fatigue analysis software Fe﹣safe was used to calculate the fatigue life of two BRB models.The results show that due to the initial geometric defects of the core plate,the reduction in fatigue life is between 3.5%and 7.1%,the reduction in cumulative plastic deformation is between 0.7%and 3.8%,in addition,the instability of BRB under cyclic loading will be increased.The results also show that the initial geometric defects had no significant influence on the energy dissipation performance and low cycle fatigue performance of BRB.