Enhancement of Welded Steel Bridge Girders Susceptible to Distortion-Induced Fatigue

Distortion-induced fatigue cracks constitute a serious national problem given the large number of steel girder bridges constructed before 1985 that are affected by this type of failure. It is estimated that 90% of all fatigue-related cracks in bridges have arisen due to out-of-plane distortion (Connor and Fisher 2006). Finding, repairing, and potentially preventing fatigue cracks at details susceptible to out-of-plane distortion represents a significant expense to State departments of transportation (DOTs). This problem is exacerbated by the fact that many of the affected bridge structures carry large traffic loads, or their geographical location is such that temporary closure would cause significant disruption to the economic activity of the local residents. While a number of repair and retrofit methods have been shown to be effective in addressing this problem (Roddis and Zhao 2001; Roddis and Zhao 2003; Stallings et al. 1999; Connor and Fisher 2006), these strategies can be time-consuming, expensive to implement, and often require temporary bridge closures. There are also instances in which these methods cannot be implemented due to lack of space in the affected region of the bridge. In those cases, the use of new and/or combined techniques may present a viable method for fatigue life extension. The main objective of the proposed research is to explore the use of composite materials and hole treatments (ultrasonic impact treatment and bolt interference) to develop new retrofitting techniques aimed at extending the fatigue life of bridges with connection details susceptible to distortion-induced fatigue. The techniques that will be studied were selected because they are relatively inexpensive, easy to implement, and can be carried out without significant disruptions to traffic.


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Filing Info

  • Accession Number: 01560761
  • Record Type: Research project
  • Source Agency: Federal Highway Administration
  • Contract Numbers: TPF-5(189)
  • Created Date: Apr 22 2015 1:03AM