ANALYTICAL COMPARISON OF EFFECTS OF SOLID- FRICTION AND VISCOUS STRUCTURAL DAMPING ON PANEL FLUTTER

摘要

A Galerkin modal analysis is presented that accounts for the effects of both solid-friction and viscous structural damping on panel flutter, based on unsteady aerodynamic forces from supersonic potential flow. The eigensolutions are made by complex eigen¬value computer routines.nMarkedly different effects on the flutter boundary of the two types of structural damping are obtained. This result establishes that there is not, in general, an "equivalent viscous" damping for solid-friction damping.nFor the limiting case of the static-aerodynamic approximation, a substantially different flutter dynamic pressure is obtained for solid friction identically zero compared with solid friction approaching zero as a limit. Use of the quasi-static aerodynamic approximation eliminates that difference.