On the influence of boundary conditions on the dependence amplitude-frequency of non-linear flutter type oscillations of rectangular plate at critical speed.

Abstract

The problem of nonlinear oscillations of an isotropic rectangular plate in a supersonic gas flow is examined. The study was conducted taking into account both types of nonlinearities: wind (quadratic and cubic) and geometric (cubic). It is known that nonlinear dependence of the frequency on the amplitude of the oscillations of the plate in absence of flowing stream has a hard character, i.e. with increasing amplitude the frequency increases. In this paper it is established that the presence of flowing stream may cause both quantitative and qualitative changes of the character of noted monotonically increasing dependence. The influence of boundary conditions along the tangential directions of simply supported plate on the dependence amplitude-frequency of non-linear flutter type oscillations at critical speeds is investigated in this paper. It is shown that transmission from one type of examined dependence to another can be controlled as via the appropriate choice of both geometrical and physical parameters of aeroelastic system, as well as via the change of boundary conditions.