Bridge Fatigue Damage Assessment under Vehicle and Non-Stationary Hurricane Wind

During hurricane events, large stress cycles from the non-stationary wind and dynamic vehicle loads could possibly induce damage initiations and propagations. Utilizing the non-stationary wind field modeling techniques and the recent developed vehicle-bridge-wind dynamic analysis framework, this paper initiates the bridge fatigue damage assessment of bridges under vehicle and non-stationary extreme hurricane wind loads. The non-stationary hurricane wind is simulated as a summation of time-varying mean and fluctuating non-stationary components with a time-varying spectrum. Dynamic stresses are obtained from solving the vehicle-bridge-wind dynamic system and stress ranges and numbers of stress cycles are evaluated using the rain flow counting method. Numerical examples of a long span bridge under simulated non-stationary hurricane winds and vehicles are presented to demonstrate the effects of the dynamic loads on the bridge safety and reliability under extreme weather events.