The role of resonance in the extreme value statistics of flow-induced response

Extreme value statics (EVS) are used to predict outlying loads that greatly damage structures. EVS are commonly applied to random environmental loads, such as sea states. However, the output response from structure’s transfer function has different statistics from the input load. Accurate prediction of maximum loads require analysis of the random response, which includes considering worst-case conditions such as resonance. This work aims to investigate the EVS of the flow-induced response from the applied load and the resonance of the first bending mode. In a water tunnel, an upstream cylinder was used to shed a wake onto a cantilever fin. The tunnel flow speed was increased to allow harmonics of the cylinder’s vortex shedding frequency to excite the fin’s first bending mode. The measured response was band-pass filtered to separate stiffness-controlled and resonance frequency bands. Extreme values of each record were modeled with the Generalized Extreme Value distribution. The experimental results are investigated to provide insight on how resonance impacts EVS and the consideration of resonance in accounting for extreme responses.