作　　者： (陈永高）; (钟振宇）;

机构地区： 浙江工业职业技术学院,浙江绍兴312000

出　　处： 《公路交通科技》 2017年第9期76-85,共10页

摘　　要： 桥梁结构的模态参数主要用于桥梁结构损伤识别及使用性能评估,在桥梁健康监测系统中具有十分重要的意义。目前较为常用的模态参数识别算法是随机子空间识别算法,主要包括协方差驱动的随机子空间识别算法和数据驱动的随机子空间识别算法。在利用随机子空间算法识别桥梁结构的模态参数时,首先需人为依据稳定图来进行系统阶次的确定,通过对稳定图定阶的不断研究,发现其依然存在模态失真和计算量大这两方面的缺陷,为此提出了新的定阶算法以实现系统阶次的自适应确定。其次需要人为参与稳定图中真实模态的辨识,这不仅降低参数识别效率,还导致筛选的结果带有一定主观性。为了避免人为参与定阶和真实模态的筛选,提高模态参数识别的效率,在现有随机子空间算法的基础上引入聚类分析算法,提出了一种改进的模态参数自动化识别算法,以实现系统阶次的自动化确定和稳定图中真实模态的自动化筛选。再通过一座试验桥验证了真实模态存在的规律。最后将改进算法运用于识别实际大型斜拉桥的结构参数。结果表明:改进算法能够实现实际桥梁结构的模态参数自动化识别,且识别结果具有可靠性。 The modal parameters of bridge structure are mainly used for bridge structure damage identification and performance evaluation,which is of great significance in bridge health monitoring system. At present,the commonly used modal parameter identification algorithm is the SSI algorithm,which mainly includes Covariance-driven Stochastic Subspace Identification（ COV-SSI） algorithm and Data-driven Stochastic Subspace Identification（ DATA-SSI） algorithm. In the process of identifying the modal parameters for bridge structure by using SSI algorithm,at first,the order of the system needs to be determined by the stability diagram with human participation. However,through continuous study of order determination for stable graph,it is found that there are still 2 defects in the manipulation,i. e.,modal distortion and large calculating quantity. Therefore,a new algorithm is proposed to adaptively determine the order of the system.And then,the original SSI algorithm requires the human participation to recognizing the real mode in stable graph,therefore,this not only reduces the efficiency of parameter identification,but also leads the screening result with certain subjectivity. In order to avoid the human participation in order determination and screening of real mode,and to improve the efficiency of the modal parameter identification,an improved modalparameter automatic identification method is proposed by introducing the clustering analysis on the basis of existing SSI algorithm,thus the automatic determination of system order is implemented,and the automatic screening of the real mode in stable graph is also effectuated. Then,the law of true modal presence is verified by using a test bridge data. Finally,the proposed method is applied to a practical large cable-stayed bridge to identify the structure parameters. The result shows that the proposed method can realize the automatic identification of the modal parameters for the real bridge structure,and the identification result is reliable.

关 键 词： 桥梁工程 模态参数识别 随机子空间识别 稳定图 系统阶次 聚类分析