Dynamic response of a slender structure to thunderstorm outflow excitation through numerical analysis and full-scale monitoring

Abstract

Thunderstorm outflows have been causing damage and failure in slender light structures susceptible to dynamic excitation. With the goal of contributing to the design of wind-safer structures, researchers have proposed simplified models for the downburst wind field through wind tunnel tests and field wind data collection. In this research, the proposed wind field models were applied to calculate the dynamic response of a slender-light structure during two real case studies of downburst winds. The result was compared with the structure’s response recorded by the structural response monitoring system during the two case studies. When time-varying aerodynamic coefficients obtained from wind tunnel testing are used, the comparison of the mean response showed that the alongwind response of the structure is overestimated while the crosswind response is underestimated. In general, contrary to the crosswind response, the calculated alongwind response of the structure was comparable to the registered response with a percentage difference of not more than 25%. Outcomes highlighted the importance of a proper definition of wind field parameters such as turbulence intensity and space coherence of downburst wind as well as structural parameters such as aerodynamic coefficients and damping ratio of the structure to the prediction of the dynamic response.