Accurate modal analysis measurements with programmed sine wave excitation

Abstract Due to the development of several new dynamic analysis methods which use experimental modal analysis results as input data, these results need to be subjected to stringent accuracy demands. One of the techniques to achieve this goal is the use of stepped since excitation. Although the principle of this technique has been known for a long time, a feasible implementation, suited for testing large structures or non-linear systems, has only been possible by making full use of today's techniques in digital signal processing. In this paper, the characteristics of the method are briefly reviewed, for both single input and multiple input testing. An implementation with response adaptive definition of excitation frequency and amplitude is presented and illustrated with some examples. The impact of this method on the estimation of the modal parameters is discussed.