“类十字”双阶屈服屈曲约束支撑理论研究及数值分析

Theoretical Study and Numerical Analysis of"Cross-Like"Double Yield Buckling Restrained Braces

屈曲约束支撑是一种承载和耗能相结合的双功能抗震构件,被广泛应用于工程结构中。然而,传统屈曲约束支撑在多遇地震作用下处于弹性状态,不耗散地震能量,且不能够适应不同等级水平的地震作用。基于此,提出一种新型"类十字"双阶屈服屈曲约束支撑(DYBRB),其在小震下进入屈服耗散地震能量并为结构提供刚度,大震下耗能能力进一步提高。通过构造设计及工作原理,详细说明了DYBRB两阶段耗能的机理;通过理论分析建立了DYBRB的力学模型,给出了DYBRB支撑刚度、承载力、屈服位移的计算公式及其简化设计方法;并采用ABAQUS软件建立了DYBRB数值模型,模拟分析其抗震性能。研究结果表明:DYBRB具有更小的屈服位移和明显的分阶段耗能特征,滞回曲线饱满,能够在不同等级地震作用下为结构提供相应水平的耗能。

Buckling restrained brace is a dual-function aseismic member which combines load and energy dissipation,and is widely used in engineering structures.However,the traditional buckling restrained brace is in the elastic state and does not dissipate seismic energy under frequent earthquake actions,and cannot adapt to different levels of seismic actions.In this paper,a new type of"cross-like"double yield buckling restrained brace(DYBRB)is proposed.Under minor earthquake conditions,it yields to dissipate seismic energy and provides stiffness for the structure,and the energy dissipation capacity increases further under the condition of severe earthquake.Through the design and working principle of the structure,the mechanism of energy dissipation in DYBRB at two stages is explained in details.The mechanical model of DYBRB is built using theoretical methods,and the formulas for calculating DYBRB supporting stiffness,bearing capacity and yield displacement are given.Then a simplified design method of DYBRB is proposed.The numerical model of DYBRB is built using ABAQUS,and the seismic performance is simulated and analyzed.The results show that DYBRB has smaller yield displacement,obvious energy dissipation characteristics and full hysteretic curves at different stages,which can provide corresponding energy dissipation under different levels of earthquake.