Natural frequencies-based stochastic finite element model updating using equal weighting factors

Abstract

Though traditional deterministic finite element model updating (FEMU) methods are being used in the industry with good results, however, these methods do not include the small variations in uncertainties. These uncertainties arise due to unknown experimental errors or variability in nominally identical dynamic systems. It is necessary to resort to the stochastic finite element model updating (SFEMU) methods to deal with these problems. Although any modal parameter can be used to update a dynamic system, this paper explores the possibility of updating a dynamic system using only natural frequencies, because natural frequencies can be obtained more accurately with lesser computational cost than obtaining any other modal parameters. In this paper, stochastic finite element model updating procedure has been proposed which uses natural frequencies with equal weighting factors to perform the stochastic finite element model updating. The effectiveness of the proposed stochastic finite element model updating procedure is demonstrated by two numerical examples and one experimental example. The results show that the stochastic finite element model updating procedure using only natural frequencies with equal weighting factors can be used for accurate quantification of uncertainties in the dynamic systems.