Finite element modeling of nomex® honeycomb core carbon/epoxy composite sandwich panels

Abstract

This work is concerned with the finite element modeling of Nomex® honeycomb core and carbon/epoxy composite laminate face sandwich panel structures. One objective is the identification of a material model for the honeycomb's constituent material by model comparison with experimental test results. A detailed model of the panel structure, including the geometry of the honeycomb, was constructed. This model was loaded in the same fashion as corresponding 3-point flexion, 4-point flexion and compression experimental load tests. Linear isotropic and orthotropic Nomex® material models were evaluated by comparing simulation results with test results. Both the isotropic and orthotropic models can make the model agree reasonably well with 3-point flexion test results alone. When those 3-point flexion test identified material model parameters are used in the 4-point flexion and compression test models, they yield about 60% and 90% stiffer results than experiment, respectively. The modeling strategy used along with the material models evaluated thus provides unsatisfactory precision. The orthotropic material model nonetheless gave the best fit to experiments from the parameter sets evaluated. ? 2012 American Scientific Publishers. All rights reserved.