Non-Cantilever Fatigue Remaining-Life Simulation Software Using Probabilistic Wind Model for All Counties in Kansas

Details

• Creators:
  Al Shboul, Khalid W ; Rasheed, Hayder A.
• Corporate Creators:
  Kansas State University Transportation Center. Department of Civil Engineering
• Corporate Contributors:
  Kansas. Dept. of Transportation. Bureau of Research
• Subject/TRT Terms:
  Failure Fatigue (Mechanics) Fatigue Cracking Mathematical Prediction Mechanical Failure Overhead Traffic Signs Probability Theory Simulation Software Traffic Signs
• Publication/ Report Number:
  KS-25-01
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Kansas
• Edition:
  Final Report: October 2021 – September 2022
• Corporate Publisher:
  Kansas. Dept. of Transportation. Bureau of Research
• Abstract:
  This study presents a comprehensive tool to accurately predict the remaining fatigue life of full-span overhead highway sign support structures subjected to a long and sustained wind fluctuation. Synthetic wind time-histories were developed by superimposing cosine waves over frequencies of 3–300 Hz and randomly generated phase angles. The Kaimal spectrum was utilized to build a database of wind time histories for each daily mean wind speed in Kansas over a period of 45 years. Moreover, each wind time history was modified to capture the mean speed and high speed each day, and then the rain flow counting technique was used to extract the relationship of the wind speed versus the cycle number for a given time span from the synthetic wind time-history. Fatigue evaluations were conducted using axial truss members. Potential fatigue failure was assessed for each structural member after the stress range was amplified using an average dynamic amplification factor. Miner’s rule was used to estimate the fatigue life of the sign structure, and a computationally affordable simulation package was developed to generate wind time-histories, cycle counting, structural modeling, and fatigue life calculations. This package was used to evaluate the fatigue life of a non-cantilever sign structure in Wichita, Kansas, and predict the end-of-fatigue-life of two members in this structure. Accordingly, inspections of these members revealed the existence of unnoticed severe fatigue cracks, while other members did not show any signs of distress.
• Format:
  PDF
• Funding:
  C2197
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:8e63004decbb74b6bd9566593d57632e5af88c66352b2dbb8a43afc2232b46ce988b3d9254261acf644e192681b32b2c25446e0720ab2d427fd418ee8f1679d3
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/87451/dot_87451_DS1.pdf
• File Type:
  [PDF - 2.06 MB ]