Model updating of real structures with ambient vibration data

Abstract

It is important to develop reliable finite element models (FEMs) for real structures not only in the design-phase but also for the structural health monitoring and life-cycle management purposes. To do so, model updating is often carried out to minimise the discrepancies between FEMs and real structures. Among existing model updating approaches, sensitivity based model updating methods which can be either manual or automated, have proven to be very effective in the application of real structures and have been widely used on flexible bridge structures. However, very few studies were reported on buildings especially those with medium-rise characteristics which are often associated with complicated initial modelling and different degrees of parameter uncertainties. In addition, even-though a handful of studies has been done on manual model updating for bridge structures, not much research has taken into account the influence of external structural components on manual model updating process. To address these issues, two case studies with real structures are established in this research. One is conducted with a 10-story concrete building to demonstrate the importance of having sufficiently detailed initial FEMs in automated model updating of medium-rise buildings and effective use of boundary limits and parameter groups to maintain the physical relevance of the updated FEMs. Other is an investigation with a single span inflexible foot bridge to highlight the necessity to consider external structural components in manual model updating of inflexible structures. Both studies employ actual ambient vibration monitoring data obtained from the test structures for the model updating processes.