Modeling of Nomex honeycomb cores, linear and nonlinear behaviours

Laurent Gornet (1) , Steven Marguet (1) , Gilles Marckmann (1)

1 GeM - Institut de Recherche en Génie Civil et Mécanique

The purpose of this study is to develop tools dedicated to the design of sandwich panels involving Nomex honeycomb cores. Special attention is paid to the ability to perform full three dimensional calculations up to failure of such structures. In the first part, the determination of effective elastic properties of Nomex honeycomb cores is carried out thanks to strain based periodic homogenization technique. Using an equivalence in energy between a real honeycomb and a fictitious continuous medium, it becomes possible to evaluate the elastic behavior of Nomex cores, starting from the knowledge of the behavior of the constitutive paper. Next, relying on experimental observations , the strengths of Nomex honeycomb cores are evaluated with a linear Euler’s buckling analysis. Results are compared with data coming from manufacturers, and give satisfaction. In order to carry out these two first studies, the Nida Core software has been developed using the finite element code Cast3M from CEA. The last part deals with the modeling of the nonlinear compressive response of Nomex cores. A model based on the thermodynamics of irreversible process is proposed and the identification technique detailed. Good agreement between experimental data and computed values is obtained.

Mots clés: Nomex honeycomb core; failure; non-linear behavior; homogenization

Domaines: Mécanique des matériaux [physics.class-ph]

Laurent Gornet, Steven Marguet, Gilles Marckmann. Modeling of Nomex honeycomb cores, linear and nonlinear behaviours. Mechanics of Advanced Materials and Structures, 2007, 14 (8), pp.589-601. ⟨10.1080/15376490701675370⟩. ⟨hal-01007067v2⟩