框架剪力墙结构模态静力非线性抗震分析方法研究

Study on the modal pushover seismic analysis methods of frame-shear-wall structures

本文在模态pushover分析方法基础上推导建立了模态静力非线性分析方法,对一栋 10层框架剪力墙结构进行了静力非线性分析,提出了目标位移求解的等效单自由度体系弹塑性时程分析迭代法,计算结果与相应时程分析结果进行了比较,表明两者吻合较好,验证了本文计算方法的有效性。另外,对同一结构,计算分析了在不同水平荷载模式下的静力非线性分析结果,比较不同荷载模式对计算结果的影响,为静力非线性分析方法的推广使用提供参考。

A modal pushover analysis method(MPA) was derived, and the time-history elastoplastic iteration method was put forward to solve the target displacement of equivalent SDOF system. A 10-story frame-shear-wall structure was studied by the nonlinear dynamic method and modal pushover method, respectively. The analysis results show that the calculating errors are notably reduced with the increase of the vibration modes.When the higher modes are considered, the improvement on the error of top displacement is not as obvious as that of inter-story drift, which indicates that the higher modes have a larger effect on the inter-story drift than on the total displacement of the structures. Moreover, static push-over analysis (POA) of the same structure was performed under three distribution patterns of horizontal loads recommended by FEMA-273. Comparing the results of POA with those of MPA, it is indicated that the MPA is more accurate than the POA under all three load patterns.To those three kinds of distributions, the result of SRSS is more approximate to that of MPA,while the equivalent lateral force distribution(ELF) takes on the largest errors. The distribution patterns of horizontal load plays an important role in the calculation results.