多层框架结构地震反应分析

Analysis on Seismic Response of Multilayer Steel Frame Structures

以结构变形为指标,平面输入地震波,按照考虑和不考虑几何非线性两种情况分析了二阶效应对钢框架结构在地震作用下时程分析的影响。并改变结构层数、阻尼比,通过对结构顶层位移、层间位移值的统计量,探讨了不同作用因素对钢框架结构地震作用的影响。结果表明:在进行多遇地震下的弹性时程分析时可以不考虑二阶效应的影响,在进行罕遇地震下的弹塑性时程分析时必须考虑二阶效应的影响。钢框架结构在相同结构层数、不同阻尼比的情况下,阻尼比越大,顶层侧移值越小;在不同结构层数、相同阻尼比的情况下,结构层数越高,顶层的侧移值就越大,结构地震反应越大,二阶效应就越明显。

The second-order effect on seismic response of the steel flame structure is analyzed with the deflection as the criterion and through considering the geometric nonlinearity or not. Under the condition of changing the flood number and the damping ratio of the structure, the different influence on the seismic response is analyzed based on counting of the value of the top-floor displacement and the displacement between two floors. The result shows that the influence of the second-order effect may not be considered when analyzing the elaslic time history for the frequent earthquake, and it must be considered when analyzing the elastic-plastic time history for the unusual earthquake. Under the condition of the steel frame structure with the same floor number and the different damping ratio, the bigger the damping ratio, the smaller the value of the top-floor displacement, and under the condition of the steel frame structure with the different floor number and the same damping ratio, the higher the floor number of structure, the bigger the value of the top-floor displacement, the greater the seismic response and the more clear the second-order effect.