STRUCTURAL IDENTIFICATION USING A COMBINATION OF SUBSPACE ANALYSIS AND BLOCK SUM TRANSFORMATION

In this article a combination of the subspace method with the block sum transformation is presented. Applying the block sum transformation a measuring window of the length T can be subdivided into intervalsT* where T*is an integer part of T. The data of all subwindows are added up to only one, which can then be analysed with the subspace method. Without a loss of accuracy the number of sample points can be reduced substantially and the computing effort is minimised. Sine sweep excitation is extremely useful for the analysis of structures with neighbouring eigenfrequencies or with high damping. The application of the proposed structural identification routine is numerically and experimentally validated.