[en] The studied polypropylene foam is a multi-scale material; agglomerated grains, visible to the naked eye, are comprised of microscopic closed cells. The response of the material to a shock presents three stages; an elastic phase followed by a collapse phase and then a densification. Microtomography was used in order to better understand damage mechanisms during the stress plateau. As this technique is not fast enough to directly follow the impact deformation, interrupted impact tests were carried out by controlling the levels of the sample deformation. The results of these impact tests completed by the micro tomographic visualisation in 2D are presented and commented in this paper.
