Browse > Article
http://dx.doi.org/10.12989/sss.2015.16.3.415

A strain-based wire breakage identification algorithm for unbonded PT tendons  

Abdullah, A.B.M. (Department of Civil and Coastal Engineering, University of Florida)
Rice, Jennifer A. (Department of Civil and Coastal Engineering, University of Florida)
Hamilton, H.R. (Department of Civil and Coastal Engineering, University of Florida)
Publication Information
Smart Structures and Systems / v.16, no.3, 2015 , pp. 415-433 More about this Journal
Abstract
Tendon failures in bonded post-tensioned bridges over the last two decades have motivated ongoing investigations on various aspects of unbonded tendons and their monitoring methods. Recent research shows that change of strain distribution in anchor heads can be useful in detecting wire breakage in unbonded construction. Based on this strain variation, this paper develops a damage detection model that enables an automated tendon monitoring system to identify and locate wire breaks. The first part of this paper presents an experimental program conducted to study the strain variation in anchor heads by generating wire breaks using a mechanical device. The program comprised three sets of tests with fully populated 19-strand anchor head and evaluated the levels of strain variation with number of wire breaks in different strands. The sensitivity of strain variation with wire breaks in circumferential and radial directions of anchor head in addition to the axial direction (parallel to the strand) were investigated and the measured axial strains were found to be the most sensitive. The second part of the paper focuses on formulating the wire breakage detection framework. A finite element model of the anchorage assembly was created to demonstrate the algorithm as well as to investigate the asymmetric strain distribution observed in experimental results. In addition, as almost inevitably encountered during tendon stressing, the effects of differential wedge seating on the proposed model have been analyzed. A sensitivity analysis has been performed at the end to assess the robustness of the model with random measurement errors.
Keywords
post-tensioned bridge; unbonded tendon; wire breakage; strain variation; post-tensioning anchorage; multi-strand tendon; damage detection algorithm; automated tendon monitoring;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Abdullah, A.B.M., Rice, J.A. and Hamilton, H.R. (2014a), "Wire breakage detection using relative strain variation in unbonded posttensioning anchors", J. Bridge Eng., 10.1061/(ASCE)BE.1943-5592.0000639, 04014056.   DOI
2 Abdullah, A.B.M., Rice, J.A. and Hamilton, H.R. (2014b), "A damage detection model for unbonded post-tensioning tendons based on relative strain variation in multi-strand anchors", Proceedings of the SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, San Diego, CA, March.
3 ASTM. (2006), "Standard specification for steel strand, uncoated sevenwire for prestressed concrete", A416, West Conshohocken, PA.
4 Bartoli, I., Salamone, S., Phillips, R., Lanza di Scalea, F. and Sikorsky, C.S. (2011), "Use of interwire ultrasonic leakage to quantify loss of prestress in multiwire tendons", J. Eng. Mech. -ASCE, 137(5), 324-333.   DOI
5 Bastien, J., Marceau, D., Fafard, M. and Chabert, A. (1996), "Experimental and numerical study of multi-strands wedge anchor heads", Symposium on Post-Tensioned Concrete Structures, Concrete Society, Slough, U.K.
6 Bastien, J., Marceau, D., Fafard, M. and Ganz, H.R. (2007), "Use of FEA for design of posttensioning anchor head", J. Bridge Eng., 12(2), 194-204.   DOI   ScienceOn
7 Chen, H.L.R. and Wissawapaisal, K. (2001), "Measurement of tensile forces in a seven-wire prestressing strand using stress waves", J. Eng. Mech. -ASCE, 127(6), 599-606.   DOI
8 Corven Engineering (2002), New directions for Florida post-tensioned bridges: Vol. 1: Post-tensioning in Florida bridges, Technical Report, Florida Department of Transportation (FDOT), Tallahassee, FL, Available at http://www.dot.state.fl.us/structures/posttensioning.shtm
9 Cullington, D.W., MacNeil, D., Paulson, P. and Elliott, J. (2001), "Continuous acoustic monitoring of grouted post-tensioned concrete bridges", NDT&E Int., 34(5), 95-105.   DOI
10 Elsener, B. (2008), "Monitoring of electrically isolated post-tensioning tendons", Tailor made concrete structures, Taylor & Francis, London.
11 Fricker, S. and Vogel, T. (2007), "Site installation and testing of a continuous acoustic monitoring", Constr. Build. Mater., 21(3), 501-510.   DOI
12 Lanza di Scalea, F., Rizzo, P. and Seible, F. (2003), "Stress measurement and defect detection in steel strands by guided stress waves", J. Mater. Civ. Eng., 15(3), 219-227.   DOI
13 Lau, K., Lasa, I. and Paredes, M. (2013), "Corrosion failure of post-tensioned tendons in presence of deficient grout", Proceedings of the NACE International CORROSION 2013, Orlando, FL, March.
14 Nguyen, K.D. and Kim, J.T. (2012), "Smart PZT-interface for wireless impedance-based prestess-loss monitoring in tendon-anchorage connection", Smart Struct. Syst., 9(6), 489-504.   DOI
15 Liu, W., Hunsperger, R.G., Folliard, K., Chajes, M.J., Barot, J. and Jhaveri, D. (1999), "Detection and characterization of corrosion of bridge cables by time domain reflectometry", Proceedings of the SPIE Nondestructive Evaluation of Bridges and Highways III, Bellingham, WA.
16 Liu, W., Hunsperger, R.G., Chajes, M.J., Folliard, K.J. and Kunz, E. (2002), "Corrosion detection of steel cables using time domain reflectometry", J. Mater. Civ. Eng., 14(3), 217-223.   DOI
17 Marceau, D., Bastien, J. and Fafard, M. (2001), "Experimental and numerical studies of mono-strand anchorage", Struct. Eng. Mech., 12(2), 119-134.   DOI   ScienceOn
18 Salamone, S., Bartoli, I., Phillips, R., Nucera, C. and Lanza di Scalea, F. (2011), "Health monitoring of prestressing tendons in posttensioned concrete bridges", Transportation Research Record 2220, Transportation Research Board, Washington, DC.
19 Salamone, S., Veletzos, M.J., Lanza di Scalea, F. and Restrepo, J.I. (2012), "Detection of initial yield and onset of failure in bonded posttensioned concrete beams", J. Bridge Eng., 17(6), 966-974.   DOI
20 Scheel, H. and Hillemeier, B. (2003), "Location of prestressing steel fractures in concrete", J. Mater. Civ. Eng., 15(3), 228-234.   DOI
21 Tabatabai, H., Mehrabi, A.B. and Yen, W.P. (1998), "Bridge stay cable condition assessment using vibration measurement techniques", Proceedings of the SPIE Structural Materials Technology III: An NDT Conference, Bellingham, WA.
22 Zejli, H., Gaillet, L., Laksimi, A. and Benmedakhene, S. (2012), "Detection of the presence of broken wires in cables by acoustic emission inspection", J. Bridge Eng., 17(6), 921-927.   DOI
23 Wang, M.L., Chen, Z.L., Koontz, S.S. and Lloyd, G.M. (2000), "Magnetoelastic permeability measurement for stress monitoring in steel tendons and cables", Proceedings of the SPIE Nondestructive Evaluation of Highways, Utilities, and Pipelines IV, Bellingham, WA.
24 Yuyama, S., Yokoyama, K., Niitani, K., Ohtsu, M. and Uomoto, T. (2007), "Detection and evaluation of failures in high-strength tendon of prestressed concrete bridges by acoustic emission", Constr. Build. Mater., 21(3), 491-500.   DOI