Influence of material non-linearity on the thermo-mechanical response of polymer foam cored sandwich structures - FE modelling and preliminary experiemntal results

In this paper, the polymer foam cored sandwich structures with fibre reinforced composite face sheets will be analyzed using the commercial FE code ABAQUS/Standard® incorporating the material and geometrical non-linearity. Large deformations are allowed which attributes geometric non linearity to the model. The full stress-strain curves up to failure will be considered for the polymer foams at different temperatures in order to study the plasticity influence of polymer foam on the sandwich structures in detail. Due to stiff face sheets resting on the soft polymer core and the ratio of the stiffness of the core to polymer foam core increases with the increase temperature the problem suffers from the inherent ill-conditionality. Along with the inherent ill-conditioning, there is geometric non linearity and the material non linearity which makes the problem difficult to solve due to the convergence issues. Finally the paper will be presenting the effect of material nonlinearity accompanied with geometric non linearity on the polymer foam cored sandwich structures subjected to thermo-mechanical load