Conference proceeding
Nonlinear ultrasonic guided waves for stress monitoring in prestressing tendons for post-tensioned concrete structures
Proceedings of SPIE, v 7292(1), pp 729220-7292211
01 Mar 2009
Abstract
Many bridges, including 90% of the California inventory, are post-tensioned box-girders concrete structures. Prestressing tendons are the main load-carrying components of these and other post-tensioned structures. Despite their criticality, much research is needed to develop and deploy techniques able to provide real-time information on the level of prestress in order to detect dangerous stress losses. In collaboration with Caltrans, UCSD is investigating the combination of ultrasonic guided waves and embedded sensors to provide both prestress level monitoring and defect detection capabilities in concrete-embedded PS tendons. This paper presents a technique based on nonlinear ultrasonic guided waves in the 100 kHz - 2 MHz range for monitoring prestress levels in 7-wire PS tendons. The technique relies on the fact that an axial stress on the tendon generates a proportional radial stress between adjacent wires (interwire stress). In turn, the interwire stress modulates nonlinear effects in ultrasonic wave propagation through both the presence of finite strains and the interwire contact. The nonlinear ultrasonic behavior of the tendon under changing levels of prestress is monitored by tracking higher-order harmonics at (n ) arising under a fundamental guided-wave excitation at ( ). Experimental results will be presented to identify (a) ranges of fundamental excitations at ( ) producing maximum nonlinear response, and (b) optimum lay-out of the transmitting and the receiving transducers within the test tendons. Compared to alternative methods based on linear ultrasonic features, the proposed nonlinear ultrasonic technique appears more sensitive to prestress levels and more robust against changing excitation power at the transmitting transducer or changing transducer/tendon bond conditions.
Metrics
12 Record Views
13 citations in Scopus
Details
- Title
- Nonlinear ultrasonic guided waves for stress monitoring in prestressing tendons for post-tensioned concrete structures
- Creators
- Ivan Bartoli - University of California San DiegoClaudio Nucera - University of California San DiegoAnkit Srivastava - University of California San DiegoSalvatore Salamone - University of California San DiegoRobert Phillips - University of California San DiegoFrancesco Lanza di Scalea - University of California San DiegoStefano Coccia - University of California San DiegoCharles S Sikorsky - California State Dept. of Transportation (USA)
- Publication Details
- Proceedings of SPIE, v 7292(1), pp 729220-7292211
- Conference
- Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2009 (2009)
- Publisher
- Society of Photo-Optical Instrumentation Engineers (SPIE)
- Resource Type
- Conference proceeding
- Language
- English
- Academic Unit
- Civil, Architectural, and Environmental Engineering
- Scopus ID
- 2-s2.0-77955701111
- Other Identifier
- 991020547318204721