摘要
使用基于平均正则化功率谱密度的峰值法和模态置信因子对杭州市市民中心的关键子结构——高空钢结构连廊的动力特性进行数值模拟和现场实测比较研究。基于有限元理论建立三维有限元模型,并通过模态分析获得结构主要的频率和振型。在输入未知情况下对连廊进行动力检测。动力检测过程包括通过传感器网络和数据采集系统获得高空连廊在风荷载和地脉动等环境激励作用下的响应时程和基于实测响应时程的试验模态分析过程。在实测连廊响应时程的基础上,使用基于平均正则化功率谱密度的峰值法和半功率带宽法识别结构的主要频率、振型和阻尼比。引入模态置信因子,对计算模态信息和实测模态信息进行比较分析,以验证数值模型的准确性。研究结果可为全面了解高空钢结构连廊的动力性态、准确预测结构的动力响应提供重要依据。
Hangzhou civic center is a steel skybridge connected hexadic-tower high-rise reinforced concrete building. The 23th and 24^th stories of the six reinforced concrete towers are connected through six steel skybridges at the height of about 90 meters. In order to capture the real structural behavior of the skybridges, numerical modeling and dynamic testing were conducted using Averaged Normalized Power Spectral Density （ANPSD） and Modal Assurance Criteria （MAC）. A three dimensional finite element model was firstly created, and the several lower frequencies and modal shapes were obtained through modal analysis procedure. Based on the sensor network and data acquisition system, time response histories of the skybridge under the ambient excitation such as wind and unknown ground motion were recorded. The main frequencies, modal shapes and corresponding damping ratios of the skybridge were obtained by of the ANPSD and half-power bandwidth methods. MAC was employed to compare the calculated modal information with them extracted from the dynamic testing. The accuracy of the numerical model was evaluated. The results can be used to understand the dynamic behavior of the skybridge and to predict the dynamic response of the building in future studies.
出处
《土木工程学报》
EI
CSCD
北大核心
2009年第2期73-79,共7页
China Civil Engineering Journal
基金
上海市青年科技启明星计划 (B类) 资助 (07QB14044)
关键词
高空连廊
动力检测
有限元方法
平均正则化功率谱密度
模态置信因子
skybridge
dynamic testing
finite element method
averaged normalized power spectral density
modalassurance criteria
