Rapid Detection of Fatigue Cracking in Steel Anchor Rods using the Impulse Response Method

This project will develop and experimentally validate a nondestructive test procedure based on the impulse response method for rapid detection of fatigue cracking in auxiliary highway structure anchor rods. Work in Stage 1 will focus on the experimental and numerical development of the impulse response method as a nondestructive evaluation method for detection of fatigue cracking in steel anchor rods. Utilizing experimental testing and numerical finite element simulations, the proposed study will determine an appropriate range of stress wave frequencies for crack detection, and will evaluate/develop mechanical impact sources that are able to accurately and reliably generate the desired stress wave response. Large-scale structure-foundation connection assemblages, representative of those utilized for auxiliary highway structures, will be fabricated and tested in the laboratory. Fatigue cracks in anchor rods will be artificially generated by cyclically loading notched rods prior to casting them in concrete foundation blocks. Fatigue crack locations will be selected based on observations published in the technical literature, as well as data obtained through a survey to state departments of transportation (DOTs.) The experiments will include use of a large-scale environmental test chamber to simulate a range of environmental exposure conditions. Stage 1 will also develop robust and reliable signal processing and data interpretation algorithms for crack detection in steel anchor rods. The challenges associated with applying impulse response testing to anchor rods necessitate the application of signal processing and data interpretation algorithms that are capable of handling (a) variation in design and as-built conditions, (b) variation in crack size and location, and (c) variation in environmental exposure, all of which influence stress wave characteristics, attenuation, and reflection. The signal processing and data interpretation algorithms will seek to provide a relatively high level of sensitivity for crack detection, considering that fatigue cracks spend long periods of time as a small fraction of the anchor rod diameter. Following the laboratory work in Stage 1, a series of field trials will be conducted in Stage 2 to validate the nondestructive test procedure under actual service conditions. Pennsylvania and Delaware DOTs will provide access to auxiliary highway structures with known anchor rod damage states. The field trial experience will be used to identify remaining work to facilitate practical implementation, and to develop specifications for prototype instrumentation and procedural guidelines for inspection personnel that facilitate the transfer of this knowledge and technology to practice, therefore, ensuring that the end product is tractable and readily adaptable to routine inspection programs.


  • English


  • Status: Active
  • Funding: $121273.00
  • Contract Numbers:

    Project 20-30, IDEA

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Jawed, Inam

  • Performing Organizations:

    Lehigh University

    ATLSS Engineering Research Center
    IMBT Laboratory
    Bethlehem, PA  United States  18015-4729
  • Principal Investigators:

    Pessiki, Stephen

  • Start Date: 20140102
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 38172

Subject/Index Terms

Filing Info

  • Accession Number: 01547550
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-30, IDEA
  • Files: TRB, RiP
  • Created Date: Dec 11 2014 1:01AM