Time-domain/ Frequency-domain Dynamic Analysis of Bridge Deck to Turbulent Wind

Abstract

ABSTRACT

Time-domain/frequency-domain dynamic analyses are performed for predicting the buffeting response of a bridge deck to turbulent wind. Rational Function Approximation (RFA), Fourier Series Approach (FSA), and Unified Approach are utilized to define self-excited forces in time-domain. The three different methodologies approximate the aerodynamic transfer functions between self-excited forces and responses of a bridge deck to eliminate frequency-dependent characteristics and satisfy causality condition. Aerodynamic admittance function without phase lag is considered to define buffeting force. General multi-mode analysis is conducted for frequency-domain analysis. Aforementioned dynamic analyses are applied to theoretical thin plate section with several incoming wind fluctuations. The predicted time histories of displacement and acceleration are nearly coincident among the three different approximation methods in time-domain. With respect to root mean square and peak value of the responses, the results of time-domain analysis and frequency-domain analysis are also almost identical. Application of the previously mentioned dynamic analyses to bluff section and comparison between the responses of numerical analysis and wind tunnel experiment will be addressed in a future publication.