Aeroelastic Vibration of a Steel Arch

The cause of vibration of a building with an unusual frontal profile is found to be the vortex shedding. Of the seven corrective measures considered, only the increase of the number of nodes to increase the frequency beyond that of resonance with my possible wind was finally selected. To accomplish this, guy wires were added at the sixth points. The guy wires may be easily slackened so that, with further information on lift forces at higher Reynolds numbers, the wires may be loosened at resonant wind velocity, and the results may be observed. In the process of considering corrective measures, the building was deliberately set into forced vibration, and the percent of critical damping of an unplastered versus a plastered arch was obtained. It was found that information is needed about the behavior of the lift coefficient on various shapes in higher Reynolds numbers. In addition, more knowledge is needed concerning the damping contribution of various building materials. It is concluded that whenever a building has an unusual shape or an unusually small amount of damping, the possibility of excessive vibration from vortex shedding should be considered. Methods satisfactory for structures moving through the vibration producing medium or stationary objects of low aesthetic requirements may not be acceptable.