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.

纤维增强聚合物（FRP）加固和改造钢筋混凝土构件，如梁，柱，板和桥面已经变得越来越受欢迎。 为了远程评估这种改造系统的原位完整性，需要一种高效和有效的无损检测技术（NDT）。 在这项研究中，一个强大的独立无损检测方法，利用空气中的声波集中在受损区域将被开发来检测FRP板/片下面的损伤和缺陷。 实验室标本与各种缺陷配置将受到声波阵列从近距离以及长距离。 由缺陷产生的动态响应将通过激光多普勒振动仪（LDV）收集。 该方法基于FRP-混凝土系统中的脱粘损伤和混凝土空隙引起的局部振动异常与完整区域引起的振动异常有很大不同，并且它们是损伤尺寸和力学性能的直接函数的概念。该研究代表了多学科的努力，综合了复合混凝土力学，固体中的波传播，声学和激光技术以及计算机科学。 它涉及数值模拟，模式识别，信号处理和成像与复杂的复合材料系统的行为。因此，该项目将有一个强大的智力组成部分，有可能推进这些多学科领域的科学知识，并对发展一个强大的非接触技术的FRP粘结混凝土结构的完整性评估作出重大贡献。 这项研究的结果将通过研究出版物和综合教育材料通过互联网广泛传播。 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。