A Robust Methodology for the Standoff Condition Assessment of FRP-Retrofitted Concrete Systems

FRP 加固混凝土系统防偏条件评估的稳健方法

• 批准号: 0926671
• 负责人: Oral Buyukozturk
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926671&HistoricalAwards=false
• 关键词: Robust; Methodology; Standoff; Condition; Assessment

Fiber-reinforced polymer (FRP) strengthening and retrofitting of reinforced concrete elements, such as beams, columns, slabs, and bridge decks have become increasingly popular. To remotely assess in-situ integrity of such retrofitted systems an efficient and effective nondestructive testing technique (NDT) is needed. In this research a robust standalone NDT approach utilizing an airborne acoustic wave focused on the damaged area will be developed to detect the damage and flaws underneath the FRP plates/sheets. Laboratory specimens with various defect configurations will be subjected to acoustic arrays from close as well as long distances. Dynamic responses produced by the defects will be collected by laser Doppler vibrometry (LDV). The proposed method is based on the concept that debonding damages and concrete voids in the FRP-concrete system cause local vibration anomalies that are considerably different from those caused by intact regions and that they are direct functions of the damage dimensions and mechanical properties.The proposed research represents a multi-disciplinary effort integrating knowledge from mechanics of composite concrete, wave propagation in solids, acoustic and laser technologies, and computer science. It involves numerical simulation, pattern recognition, signal processing and imaging in conjunction with complex composite material system behavior. Thus, the project will have a strong intellectual component with potential to advance scientific knowledge in these multi-disciplinary areas, and significant contribution toward the development of a robust non-contact technique for integrity assessment of FRP-bonded concrete structure. The findings from this research will be extensively disseminated through research publications and integrated educational materials through internet. The research activity will provide advanced training and research opportunity to the students working on this project.

纤维增强的聚合物（FRP）加强和改造了钢筋混凝土元件，例如梁，柱，板和桥梁甲板，已经变得越来越流行。 为了远程评估此类改装系统的原位完整性，需要有效而有效的无损测试技术（NDT）。 在这项研究中，利用集中在损坏区域的空气传播的声波中，将开发出一种强大的独立NDT方法，以检测FRP板/床单下方的损坏和缺陷。 具有各种缺陷配置的实验室标本将从近距离和长距离内进行声学阵列。 缺陷产生的动态响应将通过激光多普勒振动法（LDV）收集。 The proposed method is based on the concept that debonding damages and concrete voids in the FRP-concrete system cause local vibration anomalies that are considerably different from those caused by intact regions and that they are direct functions of the damage dimensions and mechanical properties.The proposed research represents a multi-disciplinary effort integrating knowledge from mechanics of composite concrete, wave propagation in solids, acoustic and laser technologies,和计算机科学。 它涉及数值模拟，模式识别，信号处理和成像以及复杂的复合材料系统行为。因此，该项目将具有强大的知识分子成分，具有推进这些多学科领域的科学知识的潜力，并为发展强大的非接触技术的发展做出了重要贡献，以评估FRP键入的混凝土结构的完整性评估。 这项研究的发现将通过研究出版物和通过互联网综合的教育材料进行广泛传播。 研究活动将为从事该项目的学生提供高级培训和研究机会。