Influence of Residual Stresses on the Fatigue Behaviour of an Orthotropic Steel Deck Using Fracture Mechanics Approach

The present study illustrates the fatigue behaviour with the presence of welding residual stress for an orthotropic steel deck bridge subjected to a range of traffic loads. The fatigue estimation methodology adopted integrates the concept of fracture mechanics with rainflow counting. Numerical models in commercially available finite element software along with rainflow counting algorithm as per ASTM standards are explicitly developed. Fatigue failure due to welding residual stresses has been reported extensively in the literature, so its evaluation would facilitate understanding the distribution and determining the stress concentrations essential in designing OSD bridge structures. The existing Mingzhu Bay bridge is considered to understand its behaviour under various traffic loads. The results emphasize the need to consider residual stress effects while evaluating the fatigue life of OSD bridges. Results showed that the initial fatigue life of concern points decreased significantly with welding residual stresses, with the fatigue life of OSD dropping from \(4.6\times {10}^{6}\) cycles to \(1.0\times {10}^{3}\) cycles for an initial crack length of 0.1 mm.