Rail Neutral Temperature/Buckling Detection in Continuous Welded Rail (CWR)

Concept prototype for Wayside Rail NT Measurement
Measurement of NT from UCSD/FRA Large-scale Rail Testbed
The UCSD/FRA Large-scale Rail NT/Buckling Testbed

Funding:

  • Department of Transportation/Federal Railroad Administration
  • Burlington Northern Santa Fe (BNSF) Railway, Union Pacific (UP), Norfolk Southern (NS) (in-kind)

Collaborators:

  • Prof. Chia-Ming Uang, UCSD
  • Prof. Alessandro Marzani, University of Bologna
  • Volpe National Transportation Center
  • Prof. Pau, University of Rome – La Sapienza

Purpose:

To develop a wayside system to measure, in-situ, the Neutral Temperature (zero-thermal-stress temperature) of rails without the need for unfastening the rail and without a reference measurement.

Synopsis:

Most modern railways use Continuous Welded Rail (CWR). A major problem in these structures is the almost total absence of expansion joints that can create buckling in hot weather and breakage in cold weather.  According to FRA Safety Statistics data, between 2009 and 2013, track alignment (buckled/sunkink) was the fifth cause of US train accidents (144 counts), with the highest associated damage cost ($76M) within the category of Track, Roadbed and Structures, and causing 144 derailments. Unfortunately, the problem of rail thermal buckling was particularly felt in the summer of 2012 due to the extremely warm temperatures affecting the country, and the (allegedly) resulting derailments in Junction City, KS, DC Metro, and Glenview-Northbrook, IL.  A related critical parameter is the rail Neutral Temperature (NT) – the temperature at which the net thermal longitudinal force in the rail is zero. To ensure safety of operation in CWR, information on the level of stress in the rail (or NT) is critical. The railroads are still searching for a method for in-situ identification of the rail NT in a manner that does not disrupt normal traffic operations.

UCSD is working on a technique which uses specific properties of the rail dynamics (high-frequency waves in their nonlinear regime) which are particularly sensitive to the state of thermal stress in the rail.  An experimental prototype (Rail-NT) has been developed and tested at UCSD’s Large-Scale Rail Buckling Facility and in the field with participating railroads (BNSF, UP, NS). Further development of the Rail-NT prototype is ongoing, based on the lessons learnt from the field tests.

Selected publications:

Nucera, C. and Lanza di Scalea, F., “Nondestructive Measurement of Neutral Temperature in Continuous Welded Rails By Nonlinear Ultrasonic Guided Waves,” Journal of the Acoustical Society of America, in press, 2014.

Nucera, C. and Lanza di Scalea, F., “Modeling of Nonlinear Guided Waves and Applications To Structural Health Monitoring,” ASCE Journal of Computing in Civil Engineering, Special Issue on Computing, SangHyun Lee, Burcin Becerik-Gerber, and Ioannis Brilakis, eds., in press, 2014. (invited paper)

Nucera, C. and Lanza di Scalea, F., “Nonlinear Wave Propagation in Constrained Solids Subjected To Thermal Loads,” Journal of Sound and Vibration, 333(2), pp. 541-554, 2014.

Nucera, C. and Lanza di Scalea, F., “Nonlinear Semi-Analytical Finite Element Algorithm for the Analysis of Internal Resonance Conditions In Complex Waveguides,” ASCE Journal of Engineering Mechanics, 140(3), pp. 502-522, 2014.

Nucera, C. and Lanza di Scalea, F., “Nonlinear Ultrasonic Waves for Structural Health Monitoring,” CD-ROM Proceedings of the 7th European Workshop on Structural Health Monitoring, (EWSHM 2014), Nantes, France, July 8-11, pp. 1-8, 2014.

Phillips, R., Lanza di Scalea, F., Nucera, C., Fateh, M., and Choros, J., “Field Testing Of Prototype Systems For The Non-Destructive Measurement Of The Neutral Temperature Of Railroad Tracks,” Proceedings of SPIE (International Society for Optical Engineering) Smart Structures/NDE Annual International Symposium – Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, J. P. Lynch, K-W. Wang, H. Sohn, eds., San Diego, CA, March 9-13, Vol. 9061, pp. 90610J1 – 90610J12, 2014.

Nucera, C., Phillips, R., Lanza di Scalea, F., Fateh, M. and Carr, G., “RAIL-NT System for the In-situ Measurement of Neutral Temperature in CWR: Results from Laboratory and Field Tests,” Transportation Research Record: Journal of the Transportation Research Board, no. 2374, Washington DC, pp. 154-161, 2013.

Nucera, C., Phillips, R., and Lanza di Scalea, F., “Ultrasonic Guided Wave Monitoring of Railroad Tracks,” Advances in Science and Technology, 83, pp. 198-207, 2013.

Nucera, C., Phillips, R., Zhu, X., Mariani, S., Lanza di Scalea, F., Fateh, M. and Carr, G., “Nonlinear Guided Waves For Neutral Temperature Measurement In Continuous Welded Rails: Results From Laboratory And Field Tests,” Proceedings of SPIE (International Society for Optical Engineering) Smart Structures/NDE Annual International Symposium – Health Monitoring of Structural and Biological Systems VII, T. Kundu, ed., San Diego, CA, March 10-14, Vol. 8695, pp. 8695281-86952812, 2013.

Nucera, C. and Lanza di Scalea, F., “Modeling of Nonlinear Guided Waves And Applications To Structural Health Monitoring,” Computing in Civil Engineering, Proceedings of the 2013 ASCE International Workshop on Computing in Civil Engineering (IWCCE), University of Southern California, Los Angeles, pp. 105-112, June 23-25, 2013.

Nucera, C., Phillips, R., Lanza di Scalea, F., Fateh, M., Carr, G., “RAIL-NT System for the In-Situ Measurement of Neutral Temperature in CWR: Results from Laboratory and Field Tests,” Journal of the Transportation Research Board, 2013.

Nucera, C. and Lanza di Scalea, F., “Higher Harmonic Generation Analysis in Complex Waveguides via a Nonlinear Semi-Analytical Finite Element Algorithm,” Mathematical Problems in Engineering, Special Issue on New Strategies and Challenges in SHM for Aerospace and Civil Structures, Hindawi Publishing Corporation, vol. 2012, doi:10.1155/2012/365630, 16 pgs., 2012.

Phillips, R., Zhu, X., and Lanza di Scalea, F., “The Influence of Stress on Electro-mechanical Impedance Measurements in Rail Steel,” Materials Evaluation, 70(10), pp. 1213-1218, 2012.

Nucera, C., Phillips, R., Lanza di Scalea, F., Fateh, M., Carr, G., “A Wayside System for In-Situ Measurement of Rail Neutral Temperature by Nonlinear Ultrasonic Guided Waves,” Proceedings of ASME 2012 Rail Transportation Division Conference, Paper # RTDF2012-9407, Omaha, NE, October 16-18, 2012.

Bartoli, I., Phillips, R., Coccia, S., Srivasatava, A., Lanza di Scalea, F., Fateh, M. and Carr, G., “Stress Dependence of Ultrasonic Guided Waves in Rails,” Journal of the Transportation Research Board, Transportation Research Record no. 2159, pp. 91-97, 2010.

Srivastava, A., Bartoli, I., Salamone, S. and Lanza di Scalea, F., “Higher Harmonic Generation in Nonlinear Waveguides of Arbitrary Cross-section,” Journal of the Acoustical Society of America, Vol. 127(5), pp. 2790-2796, 2010.

Bartoli, I., Coccia, S., Phillips, R., Srivastava, A., Lanza di Scalea, F., Salamone, S., Fateh, M., and Carr, G., “Stress Dependence of Guided Waves in Rails,” Proceedings of SPIE Smart Structures and NDE Conference, Health Monitoring of Structural and Biological Systems IV, Vol. 7650, San Diego, CA, March 7-11, 2010.