消能减震建筑结构的附加有效阻尼比估计

为估计一栋实际消能减震建筑结构在地震作用下的附加有效阻尼比，提出了一种基于有限元模型修正技术的阻尼比估计和验证方法。考虑到结构初始有限元模型存在较大模型误差，采用基于结构振动模态参数的直接模型更新方法修正初始有限元模型，其中，对于实测振型不完整问题，利用振型扩阶方法补充完整振型。基于模态应变能概念，利用整体结构模态参数识别值，推导了油阻尼器支撑系统附加给结构的有效阻尼比和有效频率的计算公式，并估计了主体结构的频率和阻尼比。以一组实际地震动监测数据为例，采用建议方法估计有效阻尼比和有效频率，通过对比修正模型的预测响应与实际监测数据，验证了建议方法的有效性。

Estimation of equivalent damping ratios of a real-world passively controlled building structure

The estimation of equivalent damping ratios of a real-world passively controlled building structure subjected to earthquake excitation was presented in this study. It was carried out and validated by using finite element (FE) model updating techniques. Considering that the initial FE model of this building has large modelling errors, the direct model updating technique was first adopted to calibrate this FE model by using the measured modal parameters of the building and mitigate modeling errors. In addition, the mode shape expansion method was utilized to deal with the spatial incompleteness of identified incomplete mode shapes due to the limited number of sensors installed in this building. Based on the concept of modal strain energy, the equivalent damping ratios and equivalent frequencies provided by the oil damper brace system were derived analytically by using the identified system modal frequencies. Frequencies and damping ratios of the main building can be further estimated by deducting these supplemental contributions from the corresponding identified system modal parameters. At last, a set of earthquake measurements of the building was selected to demonstrate the effectiveness of the proposed approach for estimation of equivalent damping ratios and equivalent frequencies through comparing the measured and predicted seismic responses by the updated FE model.