Advanced Neutral Temperature Estimation Using Solitary Waves (ANTEUSW)

Continuous welded rails (CWRs) are usually laid under tension in order to counteract the thermal expansion that occurs in warm days. The initial state of stress is such that the rail neutral temperature (RNT), i.e. the temperature at which the net stress in the rail is zero, is comprised between 90°F and 110°F. Over the years the RNT decreases, raising the risk of buckling during the warm season. The knowledge of the RNT or of the longitudinal stress helps transportation authorities and rail operators to minimize the risk of buckling by issuing slow orders. The Advanced Neutral Temperature Estimation using Solitary Waves (ANTEUSW) system aims to be a new nondestructive evaluation (NDE) method able to estimate the neutral temperature or the longitudinal stress of CWRs anytime and anywhere with minimal traffic disruption and a single measurement. The method relies on the propagation of highly nonlinear solitary waves along a device, hereinafter called the transducer, placed in a dry point contact with the rail to be inspected and able to support the propagation of solitary waves interacting dynamically with the rail to be inspected. The research hypothesis investigated in this T-86 project was that the axial stress affects the number, amplitude and speed of the pulses reflected from the transducer- rail interface. The finite element model developed in the T-86 project and the laboratory experiments conducted to validate the model showed that: (1) the transducer necessary to apply the NDE method is easy to assemble, inexpensive, and able to provide repeatable measurements; (2) some features of the solitary waves are monotonically dependent on the rail longitudinal stress, provided that the structural behavior of CWRs is equivalent to a straight beam 3+ meters long; (3) the method works well if an accurate model of the dynamic response of CWRs to localized lateral forces is available. Although the results of this project confirmed all the research hypothesis and ANTEUSW aims to be used with minimum traffic disruption, with a few measurements that do not require day-long observations under favorable weather, and without permanent wayside installations, a major factor in achieving industry acceptance is to demonstrate the new technology in real railroads. The next steps of this research include the study of curved rails and the testing of ANTEUSW in the field in collaboration with railroads owners in order to validate the technology under service traffic.

Language

  • English

Project

  • Status: Completed
  • Funding: $99994
  • Contract Numbers:

    Project J-04, IDEA 86

  • Sponsor Organizations:

    Safety Innovations Deserving Exploratory Analysis (IDEA)

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    Transit Cooperative Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC    20001

    Federal Transit Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Fitzpatrick, Velvet

  • Performing Organizations:

    University of Pittsburgh

    Benedum Engineering Hall
    Pittsburgh, PA  United States  15261
  • Principal Investigators:

    Rizzo, Piervincenzo

  • Start Date: 20170427
  • Expected Completion Date: 0
  • Actual Completion Date: 20190101
  • Source Data: RiP Project 41867

Subject/Index Terms

Filing Info

  • Accession Number: 01643013
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project J-04, IDEA 86
  • Files: TRB, RiP
  • Created Date: Aug 2 2017 1:00AM