Identification of honeycomb sandwich properties by high-resolution modal analysis

• Published in: EPJ Web of conferences 2010-01, Vol.6, p.41005
• Main Authors: Brémand, Fabrice, Rebillat, M., Boutillon, X.
• Format: Article
• Language: English
• ISSN: 2100-014X; 2100-014X
• DOI: 10.1051/epjconf/20100641005

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 (lx,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.