Predicting Residual Fatigue Life from Short Duration Field Observations

Structural steel elements of highway bridges are vulnerable to material damage and component failure due to repetitive loading or fatigue. This paper presents the development of an empirical methodology used to estimate the time at which AASHTO code-prescribed fatigue requirements will be achieved. The method will be based on extensive strain-cycle histogram data collected over a period of 24 months from an ensemble of in-service highway bridges, located in Ohio, of various functional classifications. The histogram data is processed into a temporal representation of fatigue damage accumulation for various highway functional classes, utilizing the Palmgren-Miner rule, combined with the current AASHTO/AISC constant amplitude fatigue lifetime criteria. An algorithm is developed to calculate the estimated time at which the code-prescribed fatigue requirements will be achieved for a particular fatigue detail category, on a particular structure, from strain histogram data collected over an abbreviated time window. The results of this investigation can thus be used to estimate the expected time at which repair of fatigue damage may be necessary for a particular structure, or to identify a time at which the initiation of extraordinary inspection efforts may be warranted. Implementing the results of this project could serve to enhance public safety and provide insight into future budgetary needs for bridge repair/replacement.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 27p
  • Monograph Title: First International Conference on Fatigue and Fracture in the Infrastructure: Bridges and Structures of the 21st Century

Subject/Index Terms

Filing Info

  • Accession Number: 01091690
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 23 2008 9:26AM