In this paper, the special case of operational modal analysis (OMA) is considered, with excitation having the character of the released load, i.e. a taut rope, which is loosened rapidly during the measurement. The pretension value of the rope is unknown. The work presents the algorithm for frequency response function (FRF) estimation based on the recorded time histories of the experiment described above. The time history of unmeasured excitation was modelled as an impulse with an estimated amplitude based on recorded responses at reference points. The determination of FRF allows the use of experimental modal analysis (EMA) algorithms to identify a scaled modal model. The developed method was verified by simulation data. The results of EMA carried out based on FRFs with modelled excitation and classic OMA based on recorded time histories were compared.
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