Journal of Nondestructive Evaluation

, Volume 17, Issue 3, pp 141–152 | Cite as

Ultrasonic instrumentation for measuring applied stress on bridges

  • P. A. Fuchs
  • A. V. Clark
  • M. G. Lozev
  • U. Halabe
  • P. Klinkhachorn
  • S. Petro
  • H. GangaRao


The measurement of applied stress on bridges can provide valuable information on the condition of the structure. The conventional technique for measuring applied stress is with a strain gage. However, strain gages can be time consuming to install because first the surface must usually be prepared. On a bridge, paint removal will most likely be necessary as part of this surface preparation. When dealing with lead-based paints, which are considered hazardous waste, many time consuming removal procedures are required. Because of these factors, a device that measures applied stress without requiring paint removal could be useful. While a “clamp-on” strain gage can also be used to measure applied stress without requiring paint removal, this type of strain gage can not be used on some bridge details, such as webs of I-beams and tops of box girders. An ultrasonic technique using non-contact electromagnetic transducers provides a possible method for applied stress measurement which is not limited by the same factors as those with conventional strain gages. The transducers operate through nonconductive and conductive (lead-based) paint and work on rusted, pitted surfaces. Our previous research developed a technique for measuring applied stresses on bridges with EMATs and included many laboratory tests. This paper describes field applications of the technique on actual bridge structures, as well as additional system testing and instrument calibration in the laboratory.

Key Words

Ultrasonic EMAT applied stress strain Rayleigh wave bridge 


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  1. 1.
    A. V. Clark, P. A. Fuchs, and S. R. Schaps, Fatigue load monitoring in steel bridges with Rayleigh waves,J. Nondestr. Eval. 14:83–98 (1995).CrossRefGoogle Scholar
  2. 2.
    D. S. Hughes and J. S. Kelly,Phys. Rev. 92(5):1145 (1953).MATHCrossRefGoogle Scholar
  3. 3.
    D. Crecraft,Ultrasonics 6(2):117 (1968).CrossRefGoogle Scholar
  4. 4.
    R. B. Thompson, W.-Y. Lu, and A. V. Clark, SEM Monograph in Techniques for Residual Stress Measurement: Chapter 7, Ultrasonic Techniques, to be published by Society for Experimental Mechanics.Google Scholar
  5. 5.
    B. W. Maxfield, A. Kuramoto, and J. K. Hulbert, Evaluating EMAT designs for selected applications,Mater. Eval. pp. 1166–1183. October (1987).Google Scholar
  6. 6.
    W. Y. Lu, B. W. Maxfield, and A. Kuramoto, Ultrasonic Velocity Measurement by Correlation Method, Experimental Mechanics Conference Proceedings, June (1990).Google Scholar
  7. 7.
    R. Serway,Physics for Scientist and Engineers, 2nd Ed. (Saunders College Publishing, Philadelphia, 1986), p. 417.Google Scholar
  8. 8.
    C. Holmes, WVDOT, personal communication.Google Scholar
  9. 9.
    M. G. Lozev, A. V. Clark, and P. A. Fuchs, Application of Electromagnetic-Acoustic Transducers for Nondestructive Evaluation of Stresses in Steel Bridge Structures, Virginia Transportation Research Council, VTRC 96-R30, April (1996).Google Scholar
  10. 10.
    S. D. Downing and D. F. Socie, Simple rainflow counting algorithms,Int. J. Fatigue 4:31–40 (1982).CrossRefGoogle Scholar
  11. 11.
    N. E. Dowling, Fatigue failure prediction for complicated stress-strain histories,J. Mater., JMLSA 7(1):71–87 (1972).MathSciNetGoogle Scholar
  12. 12.
    I. Rychlik, A new definition of the rainflow cycle counting method,Int. J. Fatigue 9(2):119–121 (1987).CrossRefGoogle Scholar
  13. 13.
    P. B. Keating, J. M. Kulicki, D. R. Mertz, and C. R. Hess, Economical and Fatigue Resistant Steel Bridge Detail, Participant Notebook, National Highway Institute Course No. 13049, June (1990).Google Scholar

Copyright information

© Plenum Publishing Corporation 1998

Authors and Affiliations

  • P. A. Fuchs
    • 1
  • A. V. Clark
    • 2
  • M. G. Lozev
    • 3
  • U. Halabe
    • 4
  • P. Klinkhachorn
    • 4
  • S. Petro
    • 4
  • H. GangaRao
    • 4
  1. 1.Turner-Fairbank Highway Research CenterFederal Highway AdministrationMcLean
  2. 2.Material Reliability DivisionNational Institute of Standards and TechnologyBoulder
  3. 3.Virginia Transportation Research CouncilCharlottesville
  4. 4.Constructed Facilities CenterWest Virginia UniversityMorgantown

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