MODAL PROPERTIES IDENTIFICATION OF AN FRP PEDESTRIAN BRIDGE WITH REINFORCEMENT AT NODES AND FE MODEL

Abstract

This paper aims to investigate dynamic characteristics of an FRP truss pedestrian bridge in service by means of field vibration test and eigenvalue analysis. Pedestrian-induced vibrations are also measured and utilized to identify dynamic parameters of the bridge. A multivariate autoregressive model combined with stabilization diagram was utilized to identify modal properties of the bridge. Every node of the bridge is reinforced by stainless steel plate, and FE models considering the reinforcement by increasing Youg's modulus led to comparable frequencies and mode shapes to those from observed in the test. Moreover as a boundary condition at both ends fix model resulted in a comparable modal properties to experimental ones. This study also demonstrated that the effect of reinforcement and boundary conditions have to be properly considered in an FE model to analyaze real behaviour of the FRP bridge.