On Dynamical Assembly of Nonlinear Uniaxial Atmospheric Flight Mechanics-Revisited in Frequency Domain

Abstract

In previous research, the authors developed a nonlinear analytical solution of the low order flight system using Volterra kernels in the time domain. This paper revisits the equivalent analytical solution using Volterra kernels in the frequency domain. A two-term truncated Volterra series, which is enough to capture the quadratic and bilinear nonlinearities, is developed for first and second order generalized nonlinear single degree of freedom systems. The resultant models are given in the form of first and second kernels in the frequency domain. A parametric study of the influence of each linear and nonlinear term on kernel structures is investigated. Periodic input is then employed to quantify and qualify the nonlinear response characteristics. A uniaxial pitch motion example is presented as a low order flight dynamic system. This example shows the ability of the proposed analytical Volterra-based model over the analytical linear-based model to predict, understand, and analyze the aircraft’s nonlinear behavior.