improving modal testing measurements by identification of shaker/stinger /structure interactions

When a shaker (or exciter) connects to a structure under test (SUT), the dynamic characteris-tics of the excitation system (shaker, stinger and transducers) becomes coupled with those of the SUT. These couplings contaminate recorded measurements, especially while exciting light/flexible SUTs. The aim of this work is to consider interactions between the excitation system and the SUT to introduce a new analytical model for prediction and reduction of this systematic error. With the aid of this model, changes in the dynamic stiffness of the SUT are estimated based on the stiffness of the excitation system. The effects of excitation system lo-cation and stiffness are shown in modal testing on a free-free beam. Furthermore, influence of force transducer location is studied in the excitation system setup. The proposed method is successfully used for identification and prediction of excitation system effects on dynamic characteristics of the beam.

کلیدواژه ها:

Shaker structure interactions ، Stinger ، Dynamic stiffness matrix ، Frequency re-sponse function (FRF