Anisotropic hyperelastic constitutive modeling of in-plane finite deformation responses of commercial composite hexagonal honeycombs

This research presents the adaptation of an anisotropic hyperelastic constitutive model for predicting the experimentally observed in-plane, orthotropic, bi-modular and nonlinear-elastic responses of a commercial adhesively bonded HRP-C fiberglass/phenolic hexagonal honeycomb core. The hyperelastic constitutive model is evaluated under simple states of loading using single-element finite element analysis. The predictions of the model, including stress-strain behavior, Poisson effects, and strain energy densities, are compared with test data for the in-plane uniaxial tension/compression responses of the honeycomb core as well as the single-element model with a linear orthotropic constitutive model to highlight the effectiveness of the hyperelastic model at high strain levels. Good agreement is observed between the model predictions and test data. Tension tests in ribbon and transverse directions with the full-scale honeycomb core are also simulated to ensure the suitability of the single element model for simulations of the simple loading cases and preliminary validation process.