Practical considerations in FE model updating with artificial boundary condition frequencies

The potential effectiveness of using artificial boundary condition (ABC) frequencies in finite element model updating and structural identification has been demonstrated previously with simulated structural cases. However, the successful application of such an approach in actual structures will largely depend on the practicality to obtain high quality ABC frequencies in a real measurement environment. This paper presents a study on several practical aspects concerning the implementation of the methodology in real life applications. In particular, it examines the feasibility of using a collection of the lowest ABC frequencies for model updating, and explores possible ways to improve the quality of the measured frequency response functions and thereby the ABC frequencies. A curve fitting method and a singular value decomposition procedure are investigated in particular. Results indicate that applying an appropriate FRF processing technique can generally improve the condition for the identification of ABC frequencies. The application of the methodology incorporating ABC frequencies and using GA as the search engine on a laboratory tested beam shows encouraging outcome.