A Quantitative Non-destructive Residual Stress Assessment Tool for Pipelines

Generation 2 Materials Technology (G2MT) successfully demonstrated the eStress™ system, a powerful new nondestructive evaluation system for analyzing through-thickness residual stresses in mechanical damaged areas of steel pipelines. The eStress™ system is designed to help pipeline operators find problem areas before serious damage occurs. High levels of tensile stress are the fundamental driver for dangerous corrosion and cracking in pipelines, which can be identified and mitigated proactively. The eStress™ system, developed under U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA) Small Business Innovation Research (SBIR) Phase 1 and 2 funding, measures the pipe wall internal stresses within a damaged area, allowing operators to thoroughly inspect and analyze at-risk areas before failures occur. A key advantage of the eStress™ system is that through wall stress measurements can be taken while a pipeline is in service, which allows direct measurement of the complex stress state of the dented materials under operating conditions. This is opposed to other methods that rely on a variety of assumptions, surface measurements and computational methods to arrive at stress estimates. The eStress™ system uses an array of electromagnetic sensors to rapidly map out the stress in a pipe wall to analyze dents, bends, and other stress concentrators. The current 64-sensor array design can evaluate approximately one square foot in less than two minutes. It is also envisioned that the eStress™ system could be installed permanently along high consequence areas or other areas of concern for monitoring the dynamic stresses that come from transportation, operation, pigging, nearby industry/citizens, etc. The SBIR Phase 2 funding has enabled G2MT to advance the eStress™ system from a lab scale proof of concept to a robust, portable, battery powered system suitable for field work. The SBIR funding has enabled G2MT to hire full time electrical and mechanical engineering talent required to develop and integrate the advanced software and hardware for the 64-sensor array system. Additionally, a 3D printing system was acquired to enable rapid prototyping of sensor housings that allow the articulation of the matrix array to conform to the surface of test materials such as dented pipe. The SBIR has supported the growth of G2MT from two to eight full time employees (and four part-time employees) and the first products to market are being prepared for the end of 2014. Additional spin-off technologies from this SBIR effort include a digital strain gauge system, high-temperature hydrogen attack analysis, and other proprietary efforts that are underway.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 31p

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Filing Info

  • Accession Number: 01640209
  • Record Type: Publication
  • Contract Numbers: DTRT57-12-C-10054
  • Created Date: Jul 3 2017 11:58AM