Adaptive Identification of Operating Deflection Shapes

Abstract

In this paper we are concerned with the estimation of the operating deflection shapes (ODSs) of a system in an unsteady state.It is usually difficult to identify the ODSs, because the responses under operating conditions are not always in a steady state.Therefore, the adaptive identification scheme of the ODSs for non-stationary signals is necessary.In this paper we present a new type of subspace method that can identify well-excited frequencies and the ODSs corresponding to those frequencies.In order to prove the adaptability of this scheme for time-varying signals, we demonstrate its performance using artificially generated responses.Then we use the responese of an actual structure and show the effectiveness of this scheme with actual data.The results are in good agreement with the analytical ones and lead us to belive that the proposed scheme can be successfully used for the identification of time-varying signals