Modelling of the Behaviour of Aramid Folded Cores Up to Global Crushing

This study presents the basic ingredients needed to model the out-of-plane compression behaviour of a folded core up to the global peak load. This core is made of an aramid paper. The proposed approach is both experimental and numerical and handles the problem at different scales: fibre, paper and core scales. To have a good representation of the physics, two key points are essential. The first is the mechanical behaviour of the paper. The aramid paper can be modelled as a laminate composite. An experimental study of the paper behaviour in bending has been conducted to build a damage model for the paper. The second key point concerns the geometrical defects of the folded core. The defects, arising from the manufacturing process, are built by simulation of the folding process. The macroscopic behaviour of the core under out-of-plane compression loading is shown to be very sensitive to these defects. The results of a simulated crushing test are compared to experimental ones. A good agreement is shown.