Modal macro-strain identification from operational macro-strain shape under changing loading conditions  

变荷载下基于运行宏应变形状的宏应变模态识别（英文）

作　　者：李舒[1] 徐赵东[1,2] 王少杰[1] 吴智深[3] 

机构地区：[1]东南大学土木工程学院,南京210096 [2]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096 [3]东南大学城市工程科学国际研究中心,南京210096

出　　处：《Journal of Southeast University(English Edition)》2016年第2期219-225,共7页东南大学学报（英文版）

基　　金：The National Natural Science Foudation of China(No.51578140);the Natural Science Foundation of Jiangsu Province(No.BK20151092);Scientific Innovation Research of College Graduates in Jiangsu Province(No.CXZZ12_0108)

摘　　要：To develop modal macro-strain （ MMS ） identification techniques and improve their applicability in a continuous health monitoring system for civil infrastructures, the concept of operational macro-strain shape （OMSS） and the corresponding identification method are proposed under unknown ever-changing loading conditions, and the MMS is then obtained. The core of the proposed technique is mainly based on the specific property that the macro-strain transmissibility tends to be independent of external excitations at the poles of the system and converges to a unique value. The proposed method is verified using the experimental data from a three-span continuous beam excited by an impact hammer at different locations. The identified results are also compared with the commonly used methods, such as the peak- picking （PP） method, the stochastic subspace identification （SSI） method, and numerical results, in the case of unknown input forces. Results show that the proposed technique has unique merits in accuracy and robustness due to its combining multiple tests under changing loading conditions, which also reveal the promising application of the distributed strain sensing system in identifying MMS of operational structures, as well as in the structural health monitoring （SHM） field.为了发展宏应变模态识别技术并提高其在土木结构健康监测中的适用能力,提出了运行宏应变形状的概念及相应的获取方法,并进一步识别了宏应变模态,以适用结构处于不断变化的未知激励环境.所提新技术的核心是基于宏应变传递率函数在系统极值点独立于激励源并收敛的独特性质.通过对一个三跨连续梁结构模型进行力锤激励,对所提方法进行了试验验证,同时将识别结果与未知激励条件下最常用的峰值拾取法(PP)和随机子空间法(SSI)以及数值结果进行了对比分析.结果表明,该方法联合了多次测试数据,在不同加载工况下,其识别结果在精度和稳定性方面具有独特优势。

关 键 词：macro-stain/distributed strain fiber Bragggrating （ FBG ） operational modal analysis （ OMA ） operational deflection shape （ODS） TRANSMISSIBILITY 

分 类 号：TP317[自动化与计算机技术—计算机软件与理论]