基于ETABS的斜交密肋框架结构地震反应分析

目的研究斜交密肋框架结构在小震下的地震反应和大震下的构件屈服顺序及主体安全性能．方法运用ETABS程序对试算结构进行建模计算．通过改变框架内部密肋框格的构造形式，比较结构基本动力特性的变化规律．结果弹性地震反应分析表明，嵌入的密肋框格与外框架共同工作，提高了结构抗侧刚度，改变不利振型出现顺序，降低了平面不规则结构的平扭耦联效应，使结构整体受力更趋合理；Pushover分析表明，倾斜设置的框格杆件传力路径更直接，首先参与结构抗震，通过自身的屈服和破坏发挥耗能减震作用，结构具有先密肋框格后外框架的分步延性破坏机制，符合现代结构分灾抗震设计原则．结论斜交密肋框架结构的提出，对于改善中高地震烈度区框架结构的抗震性能具有重要意义．

Seismic Responses Analysis of Skew Multi-Ribbed Frame Structure Based on ETABS

In order to study seismic response of the skew multi-rib frame structure under small earthquake and its components yield sequence under larger earthquake, the models are calculated by ETABS program, and variation rules of basic dynamic characteristics are compared by changing the structures of multi-ribbed units. Elastic analysis shows that the multi-ribbed units can improve lateral stiffness of the frame and change the appearing sequence of unfavorable models, so the whole stress characteristics of the structure are more reasonable. Pushover analysis shows that the transmission way of inclined members is more direct to partici- pate in seismic, and the structure possess ductility destruction mechanism is the first unit, then is the outer frame,and the modem aseismic design principles of the structure are achieved. It is very significant to put forward the skew multi-ribbed open-web frame structure to improve seismic performance of the common frame structure in high earthquake intensity area.