二重刚度屈曲约束支撑-框架结构抗震性能数值模拟

Numerical Simulation on Seismic Performance of Frame Structure with Two Stiffness Buckling-restrained Braces

针对屈曲约束支撑内核屈服后刚度骤降的不足,提出二重刚度屈曲约束支撑,说明其构造、工作原理及恢复力模型,并给出其各工作阶段的恢复力表达式.采用Benchmark钢框架结构模型验证该新型支撑对结构的减震效果,通过动力时程分析得出:二重刚度屈曲约束支撑在罕遇地震下能有效抑制结构变形,且使得层间位移角分布更加均匀,耗能更加分散,可避免形成薄弱层.

The concept of two stiffness buckling-restrained braces was proposed because of the disadvantage of traditional buckling-restrained brace with its stiffness plunging after the core yield.Then,the basic structure,principle of operation and restoring force model are itillustrated.And the theoretical formula of restoring force model for each work stage is also provided.The vibration control effect of benchmark steel frame structure with new type brace is researched.Through nonlinear dynamic time-history analysis,the conclusion is that the two stiffness buckling-restrained braces could reduce story deformation of structure effectively under rare earthquake,making the distribution of inter-story drift ratio more uniform,and the energy dissipation more disperse,which could avoid the formation of weak story.