Wind Analysis of a Suspension Bridge: Identification and Finite-Element Model Simulation

Abstract

A framework for numerically predicting the wind-excited response of suspension bridges with a certain level of confidence is established by means of output only system identification, model updating, wind-response simulation, and input-output comparison. A real case study represented by the identification and analysis of a newly built suspension bridge is considered. In system identification, the estimates of the modal parameters of the structure are provided with uncertainty bounds that take into account variations in identified modal features arising from different selections of the main parameters in the implementation of the identification technique. Based on the identified modal parameters, a finite-element model of the bridge is updated via an optimization technique. The updated model is then employed for numerically predicting the wind-excited structural response. Comparison with recorded data allows to check the accuracy of the model’s predictions as well as to indicate possible strategies for refining the monitoring system and the model itself.