ESDU 91010 describes the mechanism of galloping, that is an aeroelastic response in which changes in wind load due to structure response are in-phase with the structure velocity. The concepts of soft and hard oscillators are introduced and explained, and the possibilities of across-wind, along-wind and torsional galloping are discussed. Stall galloping, wake galloping and flutter as separate mechanisms are defined and briefly described. A method is provided for estimating the wind speed for the onset of galloping (or the structural damping required to prevent galloping at a given wind speed) for a single-degree-of-fre
edom system. A technique of approximately determining the galloping onset wind speed and the maximum amplitude is suggested for force coefficient curves typical of sharp-edged sections. Typical results for onset wind speed and response are shown for typical force curves. The theoretical approach used is fully explained and a worked example illustrates its use. Methods of reducing or eliminating galloping are outlined briefly.
ESDU 91010 describes the mechanism of galloping, that is an aeroelastic response in which changes in wind load due to structure response are in-phase with the structure velocity. The concepts of soft and hard oscillators are introduced and explained, and the possibilities of across-wind, along-wind and torsional galloping are discussed. Stall galloping, wake galloping and flutter as separate mechanisms are defined and briefly described. A method is provided for estimating the wind speed for the onset of galloping (or the structural damping required to prevent galloping at a given wind speed) for a single-degree-of-freedom system. A technique of approximately determining the galloping onset wind speed and the maximum amplitude is suggested for force coefficient curves typical of sharp-edged sections. Typical results for onset wind speed and response are shown for typical force curves. The theoretical approach used is fully explained and a worked example illustrates its use. Methods of reducing or eliminating galloping are outlined briefly.
