Investigating the Effects of Corrosion on the Fatigue Life of Welded Steel Attachments

• Main Author: Soape, Jack
• Other Authors: Keating, Peter
• Format: Others
• Language: en_US
• Published: 2012
• Subjects: Corrosion; Fatigue
• Online Access: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11179

The railroad industry plays a pivotal role in commerce and greatly impacts America's economy. With this in mind, they cannot afford downtime or service interruptions due to bridge or member replacement. Corrosion of bridges causes millions of dollars each year for the railroad industry in terms of maintenance and inspection. Since a large number of these bridges are steel and their service life is typically governed by fatigue of welded details, it is important to determine the interactions of the corrosion and fatigue mechanisms. While there are differing opinions on the effects of corrosion on the fatigue life of welded steel attachments, the intent of this research is to experimentally investigate the relationship between fatigue and corrosion and determine whether this relationship is beneficial, neutral, or detrimental to the fatigue behavior of welded attachments. In order to investigate the effects of corrosion on the fatigue life of welded steel attachments, a testing methodology simulating the conditions a bridge could be expected to experience during its service life is established, executed and the results evaluated. Thirty-two specimens were subjected to cycles of corrosion and interval fatigue loading at varying corrosion times and fatigue cycles. These corrosion-fatigue specimens were then compared to the five control (non-corroded) control specimens and three pre-corroded specimens. The results show that the fatigue life of welded steel attachments is not decreased by the effects of corrosion until more than half of the cross section has been reduced. Specimens subjected to a 'pre-corrosion' period occurring in the absence of fatigue loading, then subjected to cyclic fatigue loading at a later time have drastically reduced fatigue lives.