Fatigue Testing and Analysis of Highway Bridge Welds under In-Service Variable Amplitude Loading Conditions
Event details
| Date | 28.01.2011 |
| Hour | 14:00 |
| Speaker | Assist. Prof. Scott Walbridge, Department of Civil and Environmental Engineeering, University of Waterloo, Waterloo, Canada |
| Location |
GC A 330
|
| Category | Conferences - Seminars |
This presentation will summarize two recent studies wherein steel and aluminium transverse stiffener welds were fatigue tested under simulated in-service loading conditions typical of highway bridges. The test results were then used to validate a strain-based fracture mechanics model, which was subsequently used to predict the fatigue behaviour of similar welds under a wider range of influence lines, bridge spans, and loading conditions.
The focus of the first study was steel welds – both in the “as-received” condition and “treated” to improve the fatigue performance by needle peening. The employed model was found to be particularly well-suited for analyzing the treated welds, as it considers several crack growth accelerating mechanisms, which are generally not modelled in a linear elastic analysis. Using the validated model, it was found that introducing overload trucks in the traffic simulation decreases the predicted benefit of peening. This benefit can still be substantial, however, for a wide range of loading conditions likely to be seen in highway bridges.
For the second study, calculations were performed to establish damage equivalence factors for aluminum for use with the AASHTO and CAN/CSA-S6 bridge codes. In addition, fatigue tests of aluminum welds under simulated highway bridge loading conditions were performed. The same analytical model was then validated and used to perform simulations encompassing a wider range of loading conditions. Based on this work, future research needs and possibilities for further extending the employed methodology are identified.
Practical information
- General public
- Free
Contact
- Prof. A. Nussbaumer