The remarkable lightweight potential of metal/polymer/metal sandwich sheets, especially with respect to their crushing behavior in crash-relevant structural components, offers a broad field of applications. In this study, double-hat crashboxes are manufactured based on formable steel/polymer/steel (SPS) sandwich sheets and are tested under quasi-static and dynamic axial crushing conditions. The failure modes in both cases are characterized and the influence of three different trigger geometries on these crushing failure modes are investigated in detail. In addition to the experiments, the force, energy absorption and failure behavior are analyzed applying finite element modeling (FEM) with LS-Dyna. The results are validated by the experimental observations. It can be shown, that especially the mean crushing force can be predicted well even with simplification assumptions to reduce the calculation effort. Furthermore, the main failure phenomena can be represented.