Experimental Study on Damage Identification of Dynamically Excited Structures

动态激励结构损伤识别实验研究

• 批准号: 0533223
• 负责人: Surot Thangjitham
• 金额: --
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0533223&HistoricalAwards=false
• 关键词: Experimental; Study; Damage; Identification; Dynamically

AbstractThere is an increasing interest in the vibration data-based detection, localization, andquantification of damage in civil engineering structures exposed to earthquake, wind, and otherloads. Early motivation for this was provided by the discovery of hidden damages in steelstructures caused by the 1994 Northridge and 1995 Great Hanshin (Kobe) Earthquakes, and alsoby the fact that structural element are usually inaccessible after construction. Several analyticalmethods have been proposed in the literature and still more are being developed for this.Currently simulated data are being used to check the effectiveness of these methods; however,their validation and comparison on actual experimentally obtained data is yet to be done.In this exploratory project, it is proposed to experimentally study and validate theeffectives of the autoregressive with exogenous input model, wavelet transform, eigensystemrealization algorithms (ERA), and subspace identification (SSI) approaches for comprehensivemodal and damage identification of civil engineering structures. For damage localization andquantification the flexibility and rotational flexibility matrices with and without and damage locatingvectors will be used. Further analytical improvements in these methods will also be made formore reliable damage quantification. The tests will be conducted on a scaled three-story, ninedegrees-of-freedom structure model prepared such that its stiffness properties can be changedby planned changes in one or more braces, by sudden removal of one or two braces in real-timeusing magneto-rheological dampers, and by loosening the connecting hardware at few selectedjoints. The major cost of preparing this changeable scaled model will be borne by the PIsinstitution. The scaled model will be excited at its base by the 5' by 5' shaking table at VirginiaTech. The model would also have the capability of being excited by shakers installed at any ofthe three levels. The dynamic measurements of the acceleration response will be made usingten accelerometers, three placed at each floor level in two orthogonal directions plus one on thetable.The SGER funding is being sought to identify validated damage localization andquantification methods which will be needed in a more comprehensive follow-up study. Thisfollow-up study to be proposed later will develop an integrated system consisting of the validateddamage identification techniques with online consequence prognosis followed by onlineactuation, if necessary, of a control system to maintain the performance of the structure at anacceptable level. The successful outcome of this exploratory work will also be a very useful toolfor direct practical implementation in structural diagnostics and health monitoring.The Intellectual merit of this study is in the development of experimentally verifieddamage identification (detection, localization, and quantification) schemes for a comprehensivestructural health monitoring.Broader impacts of this research will occur at two levels: theeducation and training of graduate and undergraduate students and the availability of a muchneeded tool and data to researchers and practitioners involved in structural health monitoring. Agraduate student and an undergraduate student will work on this project. The undergraduatestudent will be supported through the REU program. She/he will be selected through the Centerfor the Enhancement of Engineering Diversity (CEED) at Virginia Tech from the pool of availableAfrican American, Hispanic, American Indian, and women students. The dissemination ofinformation and data generated in this research to other students, researchers and practitionerswill be done through class room teaching, website creation, presentations in conferences, andpublications in archival journals and conference proceedings.

AbstrackThere对基于数据的振动，定位和损害的损害越来越感兴趣，暴露于地震，风和其他载荷的土木工程结构中。早期的动机是通过发现由1994年诺斯里奇和1995年大汉辛（科比）地震造成的钢塞结构中的隐藏损害所提供的。文献中已经提出了几种分析方法，并为此开发了更多的分析方法。目前正在使用模拟数据来检查这些方法的有效性。但是，他们对实际实验获得的数据的验证和比较尚未进行。在此探索性项目中，建议通过外源输入模型，波浪变换，特征系统实现算法（ERA）（ERA）以及构造（SSI）识别和损害识别和损害的构造和损害识别和损害的构造和损害。对于损坏定位和定位，将使用有或没有损坏定位向量的柔韧性和旋转柔韧性矩阵。这些方法的进一步分析改进也将成为Formore可靠的损害量化。这些测试将以缩放的三层楼高的自由结构结构模型进行，以使其刚度的刚度可以通过一个或多个括号中的一个或多个括号中的更改，通过在实时的磁磁性变形器中突然卸下一个或两个括号，并在几乎选择的选择的连接硬件中散布一个或两个括号。准备这种可变缩放模型的主要成本将由Pisinstitution承担。缩放模型将在Virginiatech的5'乘5'摇桌上激发其基础上的兴奋。该模型还可以在三个级别的任何一个级别上安装的振动者兴奋。加速响应的动态测量将使用TEN加速度计进行，每个楼层在两个正交方向上以及一个在TheTable上进行的三个。此提出的研究将在稍后提出，将开发一个集成系统，该系统由验证的DDAMAGE识别技术组成，并在线后果预后，然后在必要时进行控制系统，以保持结构的性能在不可接受的水平上。这项探索性工作的成功结果也将是一个非常有用的工具，用于在结构诊断和健康监测中进行直接实践实施。这项研究的智力优点在于开发实验验证的DDAMAGE鉴定（检测，定位和定位）方案（用于全面的研究和培训），并在两种层次的研究中进行研究，并在两种层次上进行培训。对参与结构性健康监测的研究人员和从业人员进行了助长的工具和数据。 Agradure学生和一名本科生将从事这个项目。本科生将通过REU计划支持。她/他将通过中心从弗吉尼亚理工大学的工程多样性（CEED）中心选中，从美国，西班牙裔，美洲印第安人和女学生的弗吉尼亚理工学院中。本研究中对其他学生，研究人员和从业人员产生的信息和数据的传播将通过课堂教学，网站创建，会议的演讲以及档案期刊和会议论文集的公开。