EPJ Web of Conferences 6, 41005 (2010)
https://doi.org/10.1051/epjconf/20100641005

Identification of honeycomb sandwich properties by high-resolution modal analysis

¹ LMS-CNRS, École Polytechnique, 91128 Palaiseau Cedex, France
² LIMSI-CNRS, Universite Paris-Sud, B.P. 133, 91403 Orsay Cedex, France

^a e-mail: rebillat@lms.polytechnique.fr

Abstract

A method is proposed to identify the mechanical properties of the skin and core materials of honeycomb sandwich. All the elastic coefficients and loss-factors that matter in the dynamics of a panel in the thick-plate approximation are identified. To this end, experimental natural modes (i.e. eigenmodes of the damped system) are compared to the numerical modes of a large sandwich panel (l_x,y/h ≃ 80). The chosen generic model for the visco-elastic behaviour of the materials is E (1 + jη). The numerical modes are computed by means of a Rayleigh-Ritz procedure and their dampings are predicted according to the visco-elastic model. The frequencies and dampings of the natural modes of the panel are estimated experimentally by means of a high-resolution modal analysis technique. An optimisation procedure yields the desired coefficients. A sensitivity analysis assess the reliability of the method.