Initial Analytical Investigation of Cantilever and Butterfly Steel Overhead Sign Trusses With Respect to Remaining Fatigue Life

Details

• Creators:
  Al Shboul, Khalid W ; Rasheed, Hayder A.
• Corporate Creators:
  Kansas State University Transportation Center
• Corporate Contributors:
  Kansas. Department of Transportation. Bureau of Materials and Research
• Subject/TRT Terms:
  Cantilevers Cracking Fatigue Strength Inspection Overhead Traffic Signs Sign Supports Structural Supports Traffic Signs Trusses
• Publication/ Report Number:
  K-TRAN: KSU-20-3
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Kansas
• Edition:
  Final Report August: 2019 – May 2022
• Corporate Publisher:
  Kansas. Department of Transportation. Bureau of Materials and Research
• Abstract:
  Fatigue failure of highway sign structures due to sustained wind-loading events has been recognized in many states. In fact, the American Association of State Highway and Transportation Officials specifies that the structural component should be designed for infinite life by maintaining wind-induced stress below their constant amplitude fatigue threshold. However, because existing structures are typically not designed for fatigue, the condition of all critical and fatigue-prone components must be evaluated for safety. Visual inspection requires extensive time and effort and may not detect unnoticed fatigue cracks, so growing attention has focused on analytical inspection tools to examine all critical members and connections for remaining fatigue life to ensure public safety. The reliability of these analytical tools depends on the accuracy of wind-loading models applied during the life span of the structure. This study devised a fill-interpolate-extend approach to furnish a wind-loading data ensemble for the duration of analysis. The ensemble established a reliable synthetic wind model to generate fatigue cycle counts. In addition, a comprehensive analytical framework, including structural modeling, stress extraction/processing, and fatigue damage simulation, was integrated to yield an affordable tool that is applicable to various sign structures topologies. The resulting software for non-cantilever overhead structures as well as cantilever and butterfly assemblies were successfully verified to predict real cases for fatigue damage, reflecting the in-situ condition of the structures.
• Format:
  PDF
• Funding:
  C2144
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:fc63b7f27b475a05b70dac9b26d7650a60ae8d3a5daa2cd6008eacd361b19d2b9bf1e9dd48776a34abe1533a44a19e88857187d662f9992dfee438ac90c3ac6e
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/91245/dot_91245_DS1.pdf
• File Type:
  [PDF - 2.23 MB ]