Uncertainties in the evaluation of one degree-of-freedom galloping onset

This study discusses the uncertainties inherent in the galloping onset conditions of wind-excited structural elements using error propagation techniques. The problem is dealt with considering two different technical situations: the estimate of the critical wind velocity for engineering applications and the assessment of the galloping factor derived from wind tunnel experiments over a specific structural element. In the former case, significant errors may arise from the scattering of the whole set of involved parameters. In the latter case, it is shown that the galloping factor obtained in the wind tunnel test is a random variable, unavoidably affected by uncertainties due to measuring errors and its estimation technique. In both cases, it is shown that the classic deterministic approach based on nominal values of the parameters may lead to unsafe estimations of the one degree-of-freedom galloping onset.