多层屈曲约束斜撑钢框架弹塑性分析研究

Plastic analysis on buckling restrained braced steel frame

以多层屈曲约束斜撑钢框架为主要研究对象,斜撑框架强度CB以及屈曲约束斜撑的水平力分担率β为主要研究参数,拟设计6个建筑模型,对各模型进行了基于塑性铰理论的二阶非线性时程分析,考察了强震作用下各模型各层的层间位移、层剪力、屈曲约束斜撑的塑性能量分布等。结果表明,各模型的强度CB值从0.3增大到0.5或屈曲约束斜撑的水平力分担率β值从30%增大到90%时,各模型的各层最大层间位移反应值中的弯曲变形反应值越大,这种情况上层部位更明显。随着斜撑框架强度CB值或屈曲约束斜撑的水平力分担率β值的增加,各模型的各层屈曲约束斜撑分担的剪力和各层最大层剪力比值也变大。

6 piece of building models were designed for studying the multi buckling restrained braced steel frame in this paper.The main parameters in the study included the frame strength and the level participation ratio β.Second-order nonlinear time history analyses for models are conducted based on plastic hinge theory.The parametric analysis was performed on story displacement,shear,and the energy distribution of buckling restrained brace.The results revealed that story bending deformation become more remarkable when the frame strength is increasing from 0.3 to 0.5 or the level participation ratio β from 30% to 90%,and this situation is more obvious on the upper layer.The share of shear by the buckling restrained brace and the largest story shear ratio get larger in these models as the frame strength and the level participation ratio β increasing.