NON-GAUSSIAN PROBABILITY DENSITY-FUNCTION OF SDOF LINEAR STRUCTURES UNDER WIND ACTIONS

Wind velocity is usually analytically described adding a static mean t erm to a zero mean fluctuation stationary process. The corresponding a erodynamic alongwind force acting on a single degree of freedom (SDOF) structure can be considered as a sum of three terms proportional to t he mean wind velocity, to the product between mean and fluctuating par t of the wind velocity and to the square power of the fluctuating wind velocity, respectively. The latter term, often neglected in the liter ature, is responsible for the non-Gaussian behaviour of the response. In this paper a method for the evaluation of the stationary probabilit y density function of SDOF structures subjected to non-Gaussian alongw ind aerodynamic forces is presented. The method requires first the app roximation of the non-Gaussian probability density function by means o f a C-type Gram-Charlier series expansion; the coefficients of this se ries are then evaluated using very simple linear algebraic relationshi ps once the response statistical moments or, alternatively, the cumula nts or the quasi-moments up to a fixed order have been determined. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.