可更换剪切型耗能梁段-高强钢框筒结构抗震性能分析

Investigation on seismic performance of high-strength steel fabricated steel framed-tube structure with replaceable shear type energy-dissipated beam section

传统钢框筒结构(FTS)耗能能力较差,震后难以快速恢复。为了提高传统钢框筒结构的耗能能力、经济性以及实现震后快速恢复,结合剪切型耗能梁段良好的塑性变形能力、高强钢强度高节省钢材的优势以及钢框筒结构较大的抗侧刚度,提出可更换剪切型耗能梁段-高强钢框筒结构(HSS-FTS)。为了研究和对比HSS-FTS与传统FTS的抗震性能,设计了2个不同耗能梁段布置方式的HSS-FTS算例结构以及1个FTS结构算例,采用SAP2000软件建立其有限元模型,通过推覆分析和非线性动力时程分析对有限元模型的抗震性能进行分析和对比。结果表明:结构的设计指标均能满足规范要求;在推覆过程中,HSS-FTS的耗能梁段均先屈服形成塑性铰,然后裙梁梁端逐渐屈服形成塑性铰,最后底层柱端形成塑性铰,结构达到极限状态,具有理想的屈服模式;FTS的塑性铰集中在中下部楼层的裙梁端部和个别柱端,增加了结构倒塌的风险;在大震作用下,所有算例结构的层间侧移角满足规范限值要求,且HSS-FTS比FTS具有更好的延性和耗能能力;HSS-FTS的塑性铰集中在耗能梁段,其余构件保持弹性,震后仅需更换损伤严重的耗能梁段即可实现结构功能的快速恢复。

The traditional steel frame tube structure(FTS)has poor energy dissipation capacity and is difficult to recover quickly after the earthquake.In order to improve the energy dissipation capacity and economy of the traditional steel frame tube structure and realize the rapid recovery after the earthquake,the high-strength steel fabricated steel framed-tube structure(HSS-FTS)with replaceable shear type energy-dissipated beam section was proposed considering the good plastic deformation capacity of the shear type energy-dissipated beam section,the advantages of high strength and saving steel of high-strength steel and the greater lateral stiffness of the steel framed-tube structure.In order to study and compare the seismic performance of HSS-FTS and traditional FTS,two HSS-FTS structures with different energy-dissipated beam sections and one FTS structure were designed.SAP2000 software was used to build finite element models.Through Pushover analysis and nonlinear dynamic time-history analysis,the seismic performance of the finite element model was analyzed and compared.The results show that:the design indexes of the structures can meet the requirements of the code;in the process of pushover,the energy-dissipated beam section of HSS-FTS first yields to form a plastic hinge,then the skirt beam end gradually yields to form a plastic hinge,finally the bottom column end forms a plastic hinge,and the structure reaches the limit state with an ideal yield mode;the plastic hinge of FTS is concentrated in the skirt beam end and individual column end of the middle and lower floors,which increases the risk of structural collapse;under the rare earthquake,the interlayer drift angle of all the calculation examples meets the requirements of the code limit,and HSS-FTS has better ductility and energy dissipation capacity than those of FTS;the plastic hinge of HSS-FTS is concentrated in the energy-dissipated beam section,and the rest of the members remain elastic and they can realize the rapid recovery of the structure function after the earthquake only by replacing the seriously damaged energy-dissipated beam sections.