Experimental investigation of fatigue damage in orthotropic steel deck under moving vehicles

Bridges are crucial parts of the infrastructure and play a key role in engineering fields by facilitating smooth, even traffic flow. Different types of bridges exist worldwide, each serving a distinct purpose and applying to different environmental conditions. Bridges lose their structural integrity over time and can sustain damage from various factors such as infrastructure issues and earthquakes. Bridge damage can have severe consequences, posing significant risks to infrastructure integrity, particularly fatigue damage, which results in sudden failure. Periodic inspection plays a vital role in identifying early signs of damage and extending structural integrity. Orthotropic steel decks (OSDs) are innovative and widely used structural elements whose distinct design facilitates efficient load distribution and reduces the bridge weight while ensuring superior durability and flexibility. Although many improvements in the design of the steel decks have been made, fatigue damage and cracking due to traffic loads remain essential issues. In this paper, an experimental investigation on a steel deck has been carried out to evaluate fatigue damage in the early stage. The U-rib is welded to the deck plate and diaphragm to prevent fracture during the tests. All the experimental procedures are according to the Australian Standards. The investigation involves an assessment of fatigue and stress distribution in structural details, along with applying various loads to determine the steel yield load. Furthermore, a thorough analysis is conducted on failure modes and crack patterns.