Characterization and Simulation of Divinycell H80 Closed-Cell Foam

Abstract

Modeling the fracture response of complex sandwich structures often requires an elastic-plastic model of the core to accurately predict progressive damage modes. To address the failure modes occurring in foam core materials, fracture criteria should be selected to show the applicability to be consistent with non-linear finite element analyses and the elastic-plastic response. However, this may depend on some factors including the choice of an appropriate foam yield surface, applied load path and geometric shapes of the test coupons. In this study, experiments are conducted to measure the deformation behavior of Divinycell H80 foam under compression and tension loading with a variety of sample geometries. Each test specimen was modelled using Abaqus® with the actual test dimensions and boundary conditions. The description of the elastic-plastic behavior was simulated using material parameters and hardening curve to model the entire failure of foam. Further, additional failure criteria were involved in the modelling of dog-bone and two different shapes of butterfly shear specimens. The validations show a good agreement between experiments and the selected fracture criteria involved in numerical simulations in compression specimens. For the dog-bone specimens, it was clear that the modeling combination of failure criteria and elastic-plastic material model have the ability to track the stability and fast occurrence of cracks, since the crack only propagates normal to the load axis. For modelling the 45° and 90° butterfly shear specimens, the cracks propagated with nonlinear path matched with actual crack direction in the testing. However, in the force/displacement curves, both specimen models showed a gradual decrease, as opposed to the sudden failure in the actual tests.