Health Monitoring of Multi-Strand Steel Tendons and Cable Stays for Civil Structures

主要研究者：Francesco Lanza di ScaleaCo-PI：Frieder Seible University of加州，San Diego提案编号：0221707提案标题：土木结构多股钢束和斜拉索的健康监测项目摘要监测现有建筑设施的结构健康正成为工程中越来越重要的一个方面。 结构健康监测包括确保适当的结构性能，并提供早期检测的严重损坏。 本课题的目的是开发广泛应用于索承式桥梁、预应力混凝土构件等土木结构中的多股钢绞线筋和斜拉索的健康监测方法。 该方法的最终目的是1）实时测量所施加的载荷，以及2）检测包括腐蚀和断线在内的严重损坏。 本计画将探讨利用超音波应力波作为执行这些任务的潜在候选者。研究的中间目标包括：1）分散行为的表征（2）完善了基于应力波传播速度监测的载荷测量方法; 3）评估应力波对钢绞线结构损伤的敏感性; 4）开发一种修正温度对载荷测量影响的方法。 成功完成拟议的活动将有助于确保国家重要民用基础设施组成部分，如桥梁的安全。 该项目的更广泛影响将包括教育方面。研究生将直接参与所有的研究活动。一名本科生助理也将参与该项目。 结构健康监测和非破坏性评估的主题最近已被列入UCSD的结构工程系的课程开发。 目前正在编制关于这些主题的两个课程，一个是本科生一级的，另一个是研究生一级的。 研究活动得出的相关结论将纳入这些课程的课堂讲授。 超声波测量的演示将作为课程计划实验课的一部分。

PI: Francesco Lanza di ScaleaCo-PI: Frieder Seible University of California, San DiegoProposal number: 0221707Proposal title: Health Monitoring of Multi-Strand Steel Tendons and Cable Stays for Civil StructuresProject AbstractMonitoring the structural health of existing constructed facilities is becoming an increasingly relevant aspect of engineering. Structural health monitoring includes ensuring proper structural performance and providing early detection of critical damage. This project is aimed at developing a health monitoring method for multi-wire steel strand tendons and cable stays that are widely used in civil structures such as cable-supported bridges and prestressed concrete members. The ultimate purposes of the method are 1) real-time measurement of the applied loads and 2) detection of critical damage including corrosion and broken wires. The project will investigate the use of ultrasonic stress waves as potential candidates to perform these tasks.Intermediate objectives of the research include: 1) the characterization of the dispersive behavior (velocity/frequency relationship) of stress waves propagating in multi-wire strands; 2) the perfection of a method for load measurement based on monitoring the stress wave propagation velocities; 3) the assessment of the sensitivity of stress waves to structural damage in the strands; 4) the development of a method for correcting the effects of temperature on the measurement of load. Successful completion of the proposed activities will contribute to ensuring the safety of the Nation's critical civil infrastructure components, such as bridges. Broader impacts of the project will include educational aspects. A graduate student will be directly involved in all of the research activities. An undergraduate assistant will also collaborate to the project. The topics of structural health monitoring and non-destructive evaluation have been recently included in the curriculum development of UCSD's Structural Engineering department. Two courses on these topics are being developed, one at the undergraduate level and the other at the graduate level. Relevant findings resulting from the research activities will be incorporated into the classroom lectures for these courses. Demonstrations on ultrasonic measurements in strands will be given as part of the courses' programmed laboratory sessions.