Random disturbances, airplane loads and its fatigue life

This paper presents a method of analysis of an elastic airframe under environmental stochastic disturbances, e.g. atmospheric gusts and/or airfield roughness. It is based on airframe vibrational modes and includes rigid degrees of freedom. The non-stationary aerodynamics include the Wagner and Kussner effects. Gusts can be modeled either as a one-dimensional or a two-dimensional homogeneous isotropic random field with von Kلrmلns spectral densities and a Gaussian probability distribution. The spectral responses, in turn, are used to determine samples of the corresponding random processes by a method of linear non-recursive filtration. They are meant for analyzing the fatigue life and assessing the passenger comfort of the examined airplane.