Ambient vibration testing and finite element model updating of a concrete footbridge

The paper aims to present finite element (FE) model updating process of a concrete footbridge using output-only measurement. The FE model of the structure under investigation was developed by ABAQUS before to proceed with ambient vibration testing. The natural frequencies and their associated mode shapes of the structure were identified by analyzing ambient vibrations data using frequency domain decomposition technique in ARTeMIS. Applying design of experiment technique (DOE) on selected structural parameters and manual tuning by trial and error resulted in better correlation between FE and measured modes. Subsequently, automatic updating using FEMtools based on prototype testing improved the simulated dynamic properties obtained from initial FE analysis in a meaningful way. In updating procedure, the most uncertain structural parameters i.e. stiffness values of spring supports were modified so as to acquire the best possible match between test and FE data.