基于实测数据的某高层建筑结构动力参数和气动阻尼识别

发布时间：2019-01-13 07:13

【摘要】：根据在北冕台风及汶川远震作用下某270 m高大楼顶层实测得到的加速度响应数据,对该高楼的结构动力参数和气动阻尼进行了识别。采用两种方法识别得到了该大楼的模态振动频率和阻尼比参数。一是经验模态分解(EMD)结合随机减量法(RDT)及希尔伯特黄变换法(简称EMD+RDT),另外采用了基于贝叶斯理论和快速傅里叶变换的识别方法。利用EMD+RDT法,还得到了阻尼比随加速度幅值的变化规律。两种方法识别得到了非常一致的模态振动频率结果。然而,在台风作用和地震作用下所识别的大楼阻尼比特性却表现出明显不同的特性和规律,这种不同主要是由于在台风作用下的建筑物阻尼包含了气动阻尼成分。如果把地震作用下识别得到的该高楼阻尼比作为结构阻尼比,台风条件下识别得出的阻尼比为总阻尼比,则二者相减可以作为该楼气动阻尼比的估计。
[Abstract]:Based on the acceleration response data measured on the top floor of a 270m tall building under the action of North Coronal Typhoon and Wenchuan remote earthquake, the structural dynamic parameters and aerodynamic damping of the tall building are identified. The modal vibration frequency and damping ratio parameters of the building are identified by two methods. One is empirical mode decomposition (EMD) combined with random decrement method (RDT) and Hilbert-Huang transform (EMD RDT), which is based on Bayesian theory and fast Fourier transform. The variation of damping ratio with acceleration amplitude is also obtained by using EMD RDT method. The two methods obtained very consistent modal vibration frequency results. However, the characteristics of building damping ratio identified by typhoon and earthquake show different characteristics and rules, which is mainly due to the fact that the building damping under typhoon action contains aerodynamic damping components. If the damping ratio of the tall building identified under earthquake is taken as the damping ratio of the structure and the damping ratio identified under the typhoon condition is the total damping ratio, then the subtraction of the two factors can be used as the estimation of the aerodynamic damping ratio of the building.
【作者单位】：浙江大学建筑工程学院结构工程研究所;同济大学土木工程学院结构与防灾研究所;
【基金】：国家自然科学基金资助(51578504) 浙江省公益性技术应用研究计划资助项目(2012C21059)
【分类号】：TU973

【相似文献】