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

点击翻译按钮获取中文摘要

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.