The purpose of the present paper is to study the flutter instability and forced response of a nonrotating helicopter blade model with a NACA-0012 airfoil and a pitch freeplay structural nonlinearity. In this paper, three typical combinations of linear and nonlinear structure with a linear and nonlinear (ONERA) aerodynamic model are considered. Characteristic results are used to display the limit cycle oscillation and chaotic behavior of both the flutter instability and forced response for all three cases. The effects of various initial disturbance amplitudes on the forced response behavior are discussed. Comparisons of the results for the three cases are helpful in understanding physically the nonlinear aeroelasticity phenomena and chaotic oscillations.
Airfoils;Aerodynamics;Structural analysis;Flutter (aerodynamics);