TCMS: A Software for Vibration-Based Condition Monitoring of Post-Tensioned External Tendons

Document Type : Research Article


1 M.Sc. Student, Structural Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran

2 Professor, Engineering Department, Structural Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran

3 Associate Professor, Structural Engineering Research Center, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran


This paper presents a developing open-source software, named TCMS (Tendon Condition Monitoring Software), for condition monitoring of post-tensioned external tendons. This software allows users to run a complete process with three main goals: pre-processing of the input data, system identification for modal analysis, and tensile force estimation. A new Graphical User Interface (GUI) designing tool, App-Designer, is used to create a friendly GUI on the MATLAB software environment of MathWorks. A new approach for Finite Element (FE) modeling of an experimental tendon in which the load-bearing component is separately developed from the mass and stiffness components is also presented. The FE tendon model's modal parameters are identified from modal analysis to validate the applicability of TCMS. Then, the identified mode shape ratios and frequencies are used for vibration-based tensile force estimation. A comparative study based on provided tools and FE models in TCMS is conducted on different methods for tensile force estimation. The obtained results show that the existing tensile force using different methods can be estimated with accuracy in an average range of 1 to 10%. The current version of TCMS is mainly focusing on the establishment of examined modules for tensile force estimation. The TCMS source-code and data are available online on:


Main Subjects

1.Li, D., Zhou, Z., and Ou, J. (2011) Development and sensing properties study of FRP–FBG smart stay cable for bridge health monitoring applications. Measurement, 44(4), 722-729.
2. Duan, Y.F., Zhang, R., Zhao, Y., Wing Or, S., Fan, K.Q., and Tang, Z.F. (2012) Steel stress monitoring sensor based on elasto-magnetic effect and using magneto-electric laminated composite. Journal of Applied Physics, 111(7), 07E516.
3. Wenzel, H. and Furtner, P. (2006) Damage detection and bridge classification by ambient vibration monitoring-application of Brimos at Two stay cable bridges in China. Proceedings of the 4th China-Japan-US Symposium on Structural Control and Monitoring.
4. Casas, J.R. (1994) A combined method for measuring cable forces: the cable-stayed Alamillo Bridge, Spain. Structural Engineering International, 4(4), 235-240.
5. Mehrabi, A.B. and Tabatabai, H. (1998) Unified finite difference formulation for free vibration of cables. Journal of Structural Engineering, 124(11), 1313-1322.
6. Russell, J.C. and Lardner, T.J. (1998) Experimental determination of frequencies and tension for elastic cables. Journal of Engineering Mechanics, 124(10), 1067-1072.
7. Fang, Z. and Wang, J.Q. (2012) Practical formula for cable tension estimation by vibration method. Journal of Bridge Engineering, 17(1), 161-164.
8. Sagüés, A.A., Kranc, S.C., and Hoehne, R.H. (2000) Initial Development of Methods for Assessing Condition of Post-Tensioned Tendons of Segmental Bridges (No. Final Report).
9. Sagüés, A.A., Cotrim, C., and Balakrishna, V. (2005) Vibrational Evaluation of Tendons in Segmental Sections of Sunshine Skyway Bridge Main Spans (No. BD544-03).
10. Sagüés, A.A., Kranc, S.C., and Eason, T.G. (2006) Vibrational tension measurement of external tendons in segmental post-tensioned bridges. Journal of Bridge Engineering, 11(5), 582-589.
11. Lee, J.K. and Kang, J.W. (2019) Experimental evaluation of vibration response of external
post-tensioned tendons with corrosion. KSCE Journal of Civil Engineering, 23(6), 2561-2572.
12. Kim, B.H., Park, T., Shin, H. and Yoon, T.Y. (2007) A comparative study of the tension estimation methods for cable supported bridges. International Journal of Steel Structures, 7(1), 77-84.
13. Chen, C.C., Wu, W.H., Huang, C.H., and Lai, G. (2013) Determination of stay cable force based on effective vibration length accurately estimated from multiple measurements. Smart Structures and Systems, 11(4), 411-433.
14. Chen, C.C., Wu, W.H., Leu, M.R., and Lai, G. (2016) Tension determination of stay cable or external tendon with complicated constraints using multiple vibration measurements. Measurement, 86, 182-195.
15. Wu, W.H., Chen, C.C., Chen, Y.C., Lai, G., and Huang, C.M. (2018) Tension determination for suspenders of arch bridge based on multiple vibration measurements concentrated at one end. Measurement, 123, 254-269.
16. Chen, C.C., Wu, W.H., Chen, S.Y., and Lai, G. (2018) A novel tension estimation approach for elastic cables by elimination of complex boundary condition effects employing mode shape functions. Engineering Structures, 166, 152-166.
17. Farrar, C.R. and Worden, K. (2012) Structural Health Monitoring: a Machine Learning Perspective. John Wiley & Sons.
18. Butterworth, S. (1930) On the theory of filter amplifiers. Wireless Engineer, 7(6), 536-541.
19. Chiu, H.C. (1997) Stable baseline correction of digital strong-motion data. Bulletin of the Seismological Society of America, 87(4), 932-944.
20. Felber, A.J. (1993) Development of a Hybrid Bridge Evaluation System. Ph.D. Thesis Department of Civil Engineering. University of British Columbia, Vancouver, Canada.
21. Welch, P. (1967) The use of fast Fourier transform for the estimation of power spectra: a method based on time averaging over short, modified periodograms. IEEE Transactions on Audio and Electroacoustics, 15(2), 70-73.
22. Wenzel, H. and Pichler, D. (2005) Ambient Viberation Monotoring. John Wiley.
23. Geier, R., De Roeck, G., and Flesch, R. (2006) Accurate cable force determination using ambient vibration measurements. Structure and Infrastructure Engineering, 2(1), 43-52.
24. Yapar, O., Basu, P.K. and Nordendale, N. (2015) Accurate finite element modeling of pretensioned prestressed concrete beams. Engineering Structures, 101, 163-178.
25. Zhang, D. and Ostoja-Starzewski, M. (2016) Finite element solutions to the bending stiffness of a single-layered helically wound cable with internal friction. Journal of Applied Mechanics, 83(3).
26. Stanova, E., Fedorko, G., Kmet, S., Molnar, V., and Fabian, M. (2015) Finite element analysis of spiral strands with different shapes subjected to axial loads. Advances in Engineering Software, 83, 45-58.
27. Machida, S. and Durelli, A.J. (1973) Response of a strand to axial and torsional displacements. Journal of Mechanical Engineering Science, 15(4), 241-2.