Modal parameter identification of all-GFRP composite cable-stayed footbridge in Denmark

Abstract

The aim of this paper is to investigate of dynamic characteristics of cable-stayed Fiberline Bridge in Kolding, Denmark, made entirely of Glass Fiber Reinforced Polymer (GFRP) composite. During examination based on in situ free-decay measurements and using accelerometers under human jumping the primary five natural frequencies, corresponding mode shapes and damping ratios of the footbridge were identified. The Peak Picking (PP) and Frequency Domain Decomposition (FDD) approaches were applied to identify the natural frequencies and mode shapes. The corresponding damping ratios were extracted by a linear regression on the extremes of modal decays. The estimated damping ratios were compared with published data for selected footbridges made of various conventional materials. The obtained experimental results provide a relevant data regarding the dynamic response prediction or structural health monitoring of all-GFRP composite footbridges.