摘要
在大型复杂工程结构上进行现场模态测试时,由于结构规模体量大并存在空间隔断,导致数据采集设备与传感器之间快速布设数据传输线困难。因此,有必要解决不同位置分布式同步采集设备时间精确同步问题,研发易于快速安装的分布式数据采集和无线传输设备。为此,提出基于“北斗”卫星授时的结构振动分布式同步采集算法,集成分布式同步采集硬件与研发数据在线采集和无线传输软件,获取大型复杂工程结构不同空间位置时间同步动态响应,基于随机子空间算法自动识别工程结构服役状态下真实的模态参数。在赛格大厦振动事件溯源工作中,该系统成功捕捉到5月20日12:00—13:00结构共振时第69层与桅杆底部的加速度响应,发现四次共振均以频率2.12 Hz振动主导。基于该系统在环境激励条件下的现场模态测试,识别结构前19阶动力学参数,发现频率2.12 Hz是主体结构弯扭耦合和桅杆面内对称振动模态。基于现场激振测试识别频率2.12 Hz对应的阻尼比,发现阻尼比随着振幅的增加突然减小然后逐步增加,较低的阻尼比是导致赛格大厦发生共振的原因之一。
When the field modal test on large and complex engineering structures is performed, it is difficult to quickly implement the signal transmission line between data acquisition equipment and sensors due to the large scale of the structure. Therefore, it is necessary to solve the key problem of accurate time synchronization of distributed acquisition devices in different positions and develop distributed synchronous acquisition and wireless transmission devices that are installed quickly and easily. In this paper, the distributed synchronous acquisition algorithm of structural vibration was proposed based on the ‘Beidou’ satellite timing system. The distributed synchronization acquisition hardware was integrated and the online data acquisition and wireless transmission software were developed to acquire the time synchronization dynamic response of large and complex engineering structures at different spatial positions. Based on the stochastic subspace identification algorithm, the modal parameters of engineering structures in the service state were automatically identified. During the investigation of vibration events of Saige building, the acceleration response of the 69 th floor and the bottom of the mast of the Saige building were successfully captured by the distributed synchronous acquisition system when the structure resonance occurred from 12:00 to 13:00 on 20 th, May. It is observed that the resonance vibration is mainly dominated by a 2.12 Hz signal. Based on the field modal test performed by this system under ambient vibration excitation, the first 19-order modal parameters of the structure were quickly and accurately identified. It is found that the vibration mode of 2.12 Hz represents the flexural torsional coupling mode of the main structure and the in-plane symmetrical vibration mode of the mast. Based on the field excitation test, the damping ratio of 2.12 Hz decreases suddenly and then gradually increases with the increase of the vibration amplitude. The lower damping ratio is one of the reasons
作者
胡卫华
唐德徽
李俊燕
徐增茂
王宇超
卢伟
李祚华
滕军
HU Weihua;TANG Dehui;LI Junyan;XU Zengmao;WANG Yuchao;LU Wei;LI Zuohua;TENG Jun(College of Civil and Environmental Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518000,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2022年第10期76-84,共9页
Journal of Building Structures
基金
国家自然科学基金项目(51878226,52122804,51978214)。
关键词
赛格大厦
结构健康监测
分布式同步采集
动力学参数识别
Saige building
structural health monitoring
distributed synchronous acquisition
structural dynamic identification