Fracture toughness requirements for highway bridges: past and future trends
✍ Scribed by W J Wright
- Book ID
- 105361030
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 236 KB
- Volume
- 4
- Category
- Article
- ISSN
- 1365-0556
- DOI
- 10.1002/pse.99
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Fracture toughness requirements were implemented for bridge steels during the early 1970s. The philosophy behind these requirements was to provide sufficient material toughness to prevent lower‐shelf, brittle fracture at service temperatures and load rates experienced by bridges. These requirements do not alone prevent fracture, and designers must also consider proper fatigue design, fabrication quality control, and routine in‐service inspection to insure structural safety. This fracture control plan has been effective in preventing brittle fracture in most cases, but when any aspect of the plan is not performed correctly, fracture failure still can occur in bridges.
There have been significant advances in steel making practice since the 1970s, and new grades of high performance steel (HPS) are available with vastly superior toughness compared to conventional steels. Work is underway at the Federal Highway Administration to characterize the fracture performance of these new steels using test methods that quantify ductile fracture resistance. The goal is to develop an improved fracture control plan that essentially eliminates brittle fracture as a limit state for bridges. Ultimately, this level of performance will enable designers to consider less structurally redundant design concepts, resulting in more economical structures.