A Modified Approach for Predicting Fracture of Steel Components under Combined Large Inelastic Axial and Shear Strain Cycles

Steel bridges are considered to have a superior performance under earthquakes when compared to their reinforced concrete counterpart. Such reputation stems from the fact that few steel bridges have been subjected to strong ground motion in the last decade in North America. In addition to the lack of seismic exposure of the bridges, research on the seismic performance of steel bridges' superstructure is limited to few studies. Under very large inelastic strain cycles, the bridge components could fail and threaten the integrity of the bridge. Materials undergoing very large strain can only withstand a small number of reverse loading cycles, which is termed ultra - low cycle fatigue (ULCF). The stress range in High Cycle Fatigue (HCF) characterizes the behavior when the material is subjected to stress level below the yield stress. Under the HSF mechanism, small strain increment will result in relatively larger change in stress and therefore, it is appropriate to describe the behavior using the Stress - Number of cycles approach. Conventional Low Cycle Fatigue (LCF) is used to characterize the response when the stress range close to or slightly beyond the yield point; therefore the Strain - Number of cycles curve might more applicable in this case. The Manson - Coffin equation describing the LCF behavior is currently the most popular and acceptable among different model. The objectives of the project are to: (1) collect experimental data on the fatigue response of CFRP - repaired RC girders under various service temperatures.; (2) develop finite element models for fatigue life predictions of the girders.; and (3) recommend best repair practice for increasing the fatigue life of the repaired girders.

Language

  • English

Project

  • Status: Completed
  • Funding: $116850
  • Contract Numbers:

    DTRT13-G-UTC38

  • Sponsor Organizations:

    Research and Innovative Technology Administration

    University Transportation Centers Program
    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Kline, Robin

  • Performing Organizations:

    Colorado State University, Fort Collins

    Fort Collins, CO  United States  80523
  • Principal Investigators:

    Mahmoud, Hussam

  • Start Date: 20130930
  • Expected Completion Date: 20180731
  • Actual Completion Date: 20180613
  • Source Data: MPC-446

Subject/Index Terms

Filing Info

  • Accession Number: 01528069
  • Record Type: Research project
  • Source Agency: Mountain-Plains Consortium
  • Contract Numbers: DTRT13-G-UTC38
  • Files: UTC, RiP
  • Created Date: Jun 12 2014 1:00AM