Development of a Portable Stress Measurement Instrument

This report documents the results of a project to develop an ultrasonic stress measurement (USM) instrument that provides bridge engineers with quantitative measurements of the in-situ stresses in bridge members. The total stress measured includes dead load, residual, and live load stresses. The total stress measurement provided by the USM instrument can be used to analyze the structural adequacy of bridge members in ways not possible using conventional technologies. The USM instrument uses ultrasonic birefringence to measure the total stress in a steel bridge member. The USM instrumentation developed is a portable, battery-operated system designed to be suitable for practical stress measurement in the field. It can measure the in-situ forces and resulting stress directly to provide the data needed to more accurately assess structural adequacy and ensure bridge safety. The USM instrument was developed by integrating and modifying commercially available equipment into a single portable instrument containing all components needed for the measurements. Instrument development included specialized software to automatically process birefringence data to determine the magnitude of stresses. A custom transducer fixture was designed and manufactured that supports the transducer rotation necessary for birefringence measurements. The USM instrument was tested in the laboratory and through field testing that verified the accuracy of the total stress measurement. This project represented a significant step in creation of a portable stress measurement instrument and a first-generation prototype was developed. Additional system integration is planned for making the system more portable and easier to use with the end-goal of providing a commercial instrument available to the highway bridge community.

  • Record URL:
  • Supplemental Notes:
    • This IDEA project was conducted by University of Missouri and Fuchs Consulting.
  • Authors:
    • Washer, Glenn
    • Ruiz-Fabian, Pedro
  • Publication Date: 2017-10


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 38p
  • Serial:
  • Publication flags:

    Open Access (libre)

Subject/Index Terms

Filing Info

  • Accession Number: 01660029
  • Record Type: Publication
  • Report/Paper Numbers: NCHRP IDEA Project 179
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 12 2018 8:39PM