Damping loss factor characterization of complex structures using a Green’s function-based model

Abstract

The Inhomogeneous Wave Correlation technique has been used to estimate experimentally the wavenumber of simple and complex structures. However this method is essentially focused on the real part of the wavenumber and is not always robust to measure the damping loss factor related to its imaginary part. Another correlation technique able to capture the damping effects of complex structures as function of the heading angle accurately is presented here. Instead of using an inhomogeneous plane wave, the correlation is made with a Green’s function to better take into account the behavior of the structure excited by a point force. Several results, with simulated and measured data, are compared with an analytical discrete laminate model and show the accuracy of this Green’s Function Correlation technique to recover the damping loss factor of complex structures with high damping and in the mid to high frequency range.