Quasi-static punch indentation of a honeycomb sandwich plate: experiments and modelling

Punching experiments on wide honeycomb sandwich beams were performed to evaluate the predictive capabilities of a newly developed constitutive model in structural applications. The employed constitutive model for plastically compressible orthotropic materials accounts for both non-uniform hardening and softening associated with stressing in different directions. This feature is vital when assessing the structural performance of metal sandwich plates with low density cellular cores. Pure shear and uniaxial compression tests have been carried out to identify the input stress-strain data for the constitutive model. The sandwich beam has been modeled with shell/beam elements for the face sheets and only one continuum element through-the-thickness for the honeycomb core material. Comparison of the numerical results with experimental observations validates the capability of the proposed approach based on continuum modeling of the core in capturing the main features of sandwich beam response under punch loading.