Diagnosis and Prognosis of Retrofit Fatigue Crack Reinitiation and Growth in Steel-girder Bridges for Proactive Repair and Emergency Planning

The deteriorated conditions of retrofitted fatigue cracks on old multiple-steel-girder bridge connections can cause catastrophic consequences if the crack sizes go beyond the acceptable limits and therefore may require immediate action by bridge repair planners and emergency responders. Extensive efforts have been devoted to investigating the causes behind fatigue crack initiation and growth in girder-steel bridges, and several retrofit repair schemes have been suggested and implemented in the field with varying levels of success. One effective way to stop fatigue crack growth involves drilling holes near the crack tips; however, due to uncertainties in operational loading conditions and optimal hole size, cracks can grow around these holes and cause potentially dangerous scenarios. Fatigue cracks can grow quickly and cause unexpected damage before the traditional biennial inspection can take place. Therefore, it is critical to remotely detect fatigue crack reinitiation and growth at retrofit connections to help emergency responders and repair planners determine the action that has to be taken. In the proposed project, an experimental-numerical vibration-based damage-detection methodology will be evaluated with respect to its effectiveness in capturing and predicting fatigue crack reinitiation and propagation of retrofit connections. Extended finite element (X-FEM) models of the retrofit connections will be developed in which fatigue crack growth around circular holes can be modeled and investigated. The goal of this work is to help highway bridge repair and maintenance teams develop more cost-effective repair plans and safer infrastructures. Preliminary results of a current vibration-based damage-detection methodology are very promising when it comes to the method's ability to detect fatigue cracks in field applications.

Language

• English

Project

• Status: Completed
• Funding: $29578.00
• Contract Numbers:

  DTRT12-G-UTC07

• Sponsor Organizations:

  Research and Innovative Technology Administration

  University Transportation Centers Program
  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Performing Organizations:

  University of Iowa, Iowa City

  102 Church Street
  Iowa City, IA  United States  52242
• Principal Investigators:

  Rahmatalla, Salam

• Start Date: 20130701
• Expected Completion Date: 0
• Actual Completion Date: 20141231
• Source Data: RiP Project 34765

Subject/Index Terms

• TRT Terms: Deterioration; Fatigue cracking; Finite element method; Girder bridges; Inspection; Repairing; Retrofitting; Steel bridges
• Uncontrolled Terms: Damage detection
• Subject Areas: Bridges and other structures; Design; Highways; Maintenance and Preservation; Planning and Forecasting;

Filing Info

• Accession Number: 01487967
• Record Type: Research project
• Source Agency: Mid-America Transportation Center
• Contract Numbers: DTRT12-G-UTC07
• Files: UTC, RIP
• Created Date: Jul 24 2013 1:02AM