循环荷载作用下混合式钢交错桁架结构的滞回性能试验研究

An experimental study on the hysteretic behavior of composite steel staggered truss structures under cyclic load

通过1个5层混合式钢交错桁架结构1/3缩尺模型试验,研究该结构体系在循环荷载作用下的抗震性能和破坏机理。从滞回性能、刚度退化、结构延性、吸能能力及破坏模式等方面评价该结构体系的抗震性能。试验及分析结果表明,该结构体系具有承载能力高、侧向刚度大等优点,但其延性、变形能力和耗能能力较差,且侧向刚度沿结构高度方向分布不均匀。应力测试结果表明,该结构体系塑性铰开始形成于底部2层桁架,然后向上层桁架发展,直至试件形成机构破坏,柱中未形成塑性铰,地震能量主要通过桁架构件耗散,其破坏属于梁铰机制。

The seismic behavior and failure mechanism of steel staggered truss structures, including the hysteretic behavior, rigidity degeneration, ductility and energy dissipation, under cyclic load were studied through a 1/3 scaled model test. The results indicated that composite steel staggered truss structures are advantageous in bearing capacity, lateral rigidity, while the disadvantages are in ductility, deformability, energy dissipation and non-uniform lateral rigidity along the height. The stress measurement showed that the plastic hinge first formed in the members of the truss in the second story, and then extended to upper stories, and the structure failed due to the formation of the mechanism. The plastic hinges did not form in the column until model failure, earthquake energy was mostly dissipated by the truss members, and failure of composite steel staggered truss structures was due to formation of beam hinges.