不同跨宽的外置K形支撑钢框架抗震性能分析

Analysis on Seismic Performance of External K-braced Steel Frames with Different Span Widths

目的研究外置K形支撑在钢结构中的应用,分析外置K形支撑的外置跨宽度对结构体系的抗震性能的影响.方法基于位移的抗震设计方法,建立外置K形支撑钢框架结构模型,并进行模态分析、静力弹塑性分析以及动力时程分析,研究不同跨宽的外置K形支撑钢框架抗震性能.结果在小震作用,外置K形支撑处于弹性状态,外置跨宽度越大的结构,可以为结构提供更大的侧向刚度,减小结构层位移;在大震作用下,外置支撑先于框架结构构件破坏,消耗地震能量,且破坏处位于主体结构之外,易更换支撑.结论当外置K形支撑跨宽度在1~1.5 m内,结构的承载力、刚度和抗震性能随着外置跨宽度的增加而提高.

This paper mainly studies the application of the external K-brace in the steel structure,and analyzes the influence of the external span width of the external K-brace on the seismic performance of the structure system.Based on the displacement based seismic design method,the external K-brace steel frame structure model was established,and the modal analysis,static elastic-plastic analysis and dynamic time history analysis were carried out to study the seismic resistance of the external K-brace steel frame with different span width seismic performance.Under the frequent earthquake action,the external K-brace support is in elastic state.The larger the width of the external span width is,the greater the lateral stiffness of the structure and the smaller the displacement of the structure layer can be provided.Under the rare earthquake action,the external support is prior to the damage of the frame structure,consuming seismic energy,and the damage is located outside the main structure,so it is easy to replace the support.When the width of the external K-brace support span is in the range of 1-1.5 m,the bearing capacity,stiffness and seismic performance of the structure increase with the increase of the width of the external span.