Effects of modal density in system identification using the Hilbert transform

The paper aims to review and deepen the effects of the modal density in the dynamical identification with the Complex Plane Representation (CPR) method that is based on the Hilbert transform of the motion response of mechanical systems. It is demonstrated that the strong accuracy in the identification of the modal parameters with the CPR method can be somewhat corrupted for high modal densities. Theoretical and numerical solutions are used to analyze the problem and validate the CPR results.