An average inverse power ratio method for the damping estimation from a frequency response function
Résumé
The well-known bandwidth previous termmethod,next term especially the half-previous termpowernext term bandwidth previous termmethodnext term [1], [3] and [4] (Bishop and Gladwell, 1963; Nashif et al., 1985; Yin, 2008) is probably the simplest previous termmethodnext term for the previous termdamping estimation from a frequency response functionnext term (FRF). This previous termmethodnext term is quite efficient for simple model test cases when modes are well separated. However, the determination of the two previous termfrequenciesnext term corresponding to previous termanext term given previous termpower rationext term value requires numerical interpolations of experimental discrete data of previous termfrequency response functions.next term In this paper, an previous termaverage inverse power ratio methodnext term is proposed. The previous termaveragenext term value is computed at two previous termfrequenciesnext term symmetrically located from previous termanext term peak amplitude previous termfrequency. Then the damping rationext term can be estimated by using previous termanext term formula similar to that of the bandwidth previous termmethod.next term In this way, the previous termdamping estimationnext term becomes straightforward from the FRF data. This new previous termmethodnext term could be useful for engineers in practice due to its extreme simplicity.