Fatigue damage evaluation of broad-band Gaussian and non-Gaussian wind load effects by a spectral method

Abstract

This study presents fatigue damage evaluation of broad-band Gaussian and non-Gaussian wind load effects by a spectral method proposed in Benasciutti and Tovo (2005) [4]. The wind load effects considered are alongwind, crosswind and their coupled responses of tall buildings, and wind pressures on claddings. Following this spectral method, the rainflow counting damage is approximated by a linear combination of its upper and lower bounds. A refined formulation for determining the combination factor is proposed, which depends on bandwidth parameters in terms of process spectral moments. For non-Gaussian wind load effects, research emphasis is placed on the modeling of translation function which relates the non-Gaussian process with an underlying Gaussian process and is essential for non-Gaussian fatigue damage evaluation. Both moment-based translation model and the model by a direct curve fitting are addressed for a wide range of non-Gaussian characteristics, including a newly developed translation model for hardening non-Gaussian processes. The effectiveness and accuracy of the spectral method for broad-band Gaussian and non-Gaussian processes are demonstrated through comparison with the results from time domain rainflow counting method.