Influence of Material Toughness on Fracture Reliability in Steel Bridges

The AASHTO LRFD Bridge Design Specifications do not explicitly include a quantifiable fracture limit state. Fracture control in steel bridges is currently based on mitigating potential fracture initiators through proper structural detailing and specifying minimum impact toughness for base material. This fracture control approach has been successful in minimizing the number of fractures in steel bridges designed since its inception; however, the structural reliability against brittle fracture has not been previously established. Accordingly, the objective of this study is to quantify the relationship between material toughness and fracture reliability in steel bridge members, considering the probabilistic distribution of fracture toughness and applied stress for a variety of structural steels and assumed crack sizes. The master curve approach is used to account for the probabilistic distribution of fracture toughness, and reliabilities are determined using Monte Carlo simulation and the Hasofer-Lind approach. The results indicate that the fracture reliability for modern bridge steels is consistent with the reliability of AASHTO strength limit states, and that certain steels currently available on the market can provide enough reliability against fracture to essentially eliminate brittle fracture as a limit state of concern.

• Record URL:
  https://www.fhwa.dot.gov/bridge/steel/pubs/hif18047.pdf
• Corporate Authors:

  Modjeski and Masters, Incorporated

  Mechanicsburg, PA  United States  17050

  Federal Highway Administration

  Office of Infrastructure
  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  ATLSS Center, Lehigh Univ.

  ,    
• Authors:
  • Artmont, Frank A
  • Murphy, Thomas P
  • Sause, Richard
  • Bocchini, Paolo
  • Mertz, Dennis
• Publication Date: 2018-10

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Figures; References; Tables;
• Pagination: 46p

Subject/Index Terms

• TRT Terms: Failure; Fracture mechanics; Fracture properties; Monte Carlo method; Reliability; Steel bridges
• Subject Areas: Bridges and other structures; Highways; Materials;

Filing Info

• Accession Number: 01706480
• Record Type: Publication
• Report/Paper Numbers: FHWA-HIF-18-047
• Contract Numbers: DTFH61-11-H-00027
• Files: TRIS, ATRI, USDOT
• Created Date: May 28 2019 4:50PM