INCLUSION OF MECHANICAL DAMPERS IN THE MULTIMODAL FLUTTER ANALYSIS OF SLENDER STRUCTURES

Abstract

Sometimes slender structures are reinforced with mechanical dampers to reduce the vibrations caused by aeroelastic phenomena like flutter. However the formulation of flutter analysis only considers the classical damping ratio to take into account the structural damping. This paper explains the procedure used for adding mechanical dampers with a known constant to the analysis software FLAS. This code was developed at Universidade da Coruña to calculate the critical wind speed for flutter instability. An example of a solar tracker with two rows of flat panels is shown. In this slender structure two mechanical dampers are used to reduce the vibrations caused by the wind in structure interaction. The solar tracker has been studied for five different positions of the angle of attack. Results of flutter speed for several values of the dampers constant and global structural damping ratio are presented.