Fatigue assessment of an existing orthotropic steel deck to comply with future traffic intensity

Orthotropic Steel Decks (OSDs) are widely used in long span bridges because of their extremely light weight when compared to their load carrying capacity. These deck types typically consist of a grillage of closed trapezoidal longitudinal stiffeners and transverse web stiffeners, welded to a deck plate. As a result, fatigue problems occur due to...

Fatigue damage evaluation using S-N curves obtained by different data fitting methods

This paper investigates the differences in the predicted fatigue life of transverse butt weld joints and cover-plated beams considering statistically based fitting methods on fatigue test data and comparing the results with the S-N relation proposed in international standards. The test data fitting are performed by employing the Least Square...

Including load sequence effects in the fatigue damage estimation of an offshore wind turbine substructure

Retardation is a load sequence effect, which causes a reduced fatigue crack growth rate after an overload is encountered. Retardation can be cancelled when the overload is followed by an underload. The net effect is beneficial to the fatigue lifetime of Offshore Wind Turbines (OWTs). To be able to take this into account, computationally...

Remaining fatigue life time assessment of welded and braced side branches

High cycle fatigue failure is likely to occur when a rather undamped offshore installation is operated over a long period of time. Especially welded parts are vulnerable to fluctuating stress ranges, if the structural components, such as the small bore side branches, are loaded in resonance. In particular, the welded connections at e.g. tie-in...

Crack growth prediction of deck plate-stiffener joints in orthotropic steel bridge decks

Orthotropic deck structures are used in many steel bridges. Due to the typical detailing applied as around 1970, a significant number of deck structures constructed in that period suffer from fatigue damage. In many countries cracks have been detected, in particular in the weld between the deck plate and the trapezoidal stiffener. These cracks...

Survey on damage mechanics models for fatigue life prediction

Engineering methods to predict the fatigue life of structures have been available since the beginning of the 20th century. However, a practical problem arises from complex loading conditions and a significant concern is the accuracy of the methods under variable amplitude loading. This paper provides an overview of existing fatigue damage models...

Fatigue of bridges with a horizontal rotation axle under random wind load

The operating mechanisms of movable bridges are subjected to various types of fluctuating loads which may induce fatigue damage. Wind load acting on the bridge deck - when the bridge is open - is one of the important load types. A wind load model is proposed that can be used in the fatigue design verification. The model is based on wind...