## 6 Simulation Results  
The investigation of the non-linear structural behavior of several types of sandwich construction subjected to the given blast loading provides the basis for an assessment of the protection potential of the selected core topologies. Details of the simulation results are summarized in the following charts. These charts contain the temporal evolution of the protection-relevant mechanical parameters, such as the displacements and accelerations that occurred on the top and bottom sides in the center of the panel, as well as the reaction forces that were observed at the supporting structure (RF\({}_{3}\)) and the plastically dissipated energy (ALLPD) in the time interval under consideration. In addition, a comparative compilation of the respective maximum values-which are normalized by individually dividing them by the corresponding reference values for the monolithic reference plate of the same area and mass-enables a clear qualitative classification of the different design strategies. The aforementioned values represent typical mechanical parameters useful for assessing structural performance and estimating possible physical injury in dynamic stress situations. Figure 14: Exemplary presentation of the FE-mesh as well as bearing and contact conditions. For purposes of illustration, the discrete evaluation points are shown in Figure 15. At the reference nodes, the respective displacements of the cover surfaces in the center of the field (\(u_{3,\text{top}}\) and \(u_{3,\text{bot}}\)) and the corresponding accelerations (\(a_{3,\text{top}}\) and \(a_{3,\text{bot}}\)) were evaluated. For the homogeneous monolithic reference plate, the two evaluation points on the shell center surface coincide so that it holds \(u_{3,\text{top}}\ =\ u_{3,\text{bot}}\) and \(a_{3,\text{top}}\ =\ a_{3,\text{bot}}\). In addition to the measurable local and integral mechanical variables, the shape of the global (system) deformation also showed considerable differences for the investigated sandwich variants. Structural integrity can, however, play an important role in the application of protective devices, depending on the field of application and requirement profile. Figure 16 shows the deformation of the monolithic reference panel as a result of the specified explosion load. The largest deflections were observed at the measuring points in the center of the panel (RP\({}_{\text{top}}\) and RP\({}_{\text{bot}}\)). In contrast, various sandwich structures--in some cases, despite good mechanical characteristic values--exhibited considerable deformations and failure states. Some exemplary deformation states for all three classes of core topology are shown in Figure 17. A more comprehensive overview can be found in Appendix A. The simulations show that the group of honeycomb cores was, without exception, the most resistant and robust sandwich type. For honeycomb cores, the majority of the deformations occurred in the unsupported area, whereas the supported part remained almost unchanged even after loading. Both deformations in the core area and global structure deformations were comparatively minor. None of the considered honeycomb core sandwich structures showed cracks in the cover surfaces throughout the finite element simulations. Figure 16: Deformation of the monolithic reference plate under blast loading (t = 0.6 ms). Figure 15: Position of the discrete evaluation points in the center of the panel on the upper and lower cover surfaces. For the 3D lattice cores, in addition to their dependence on the lattice cell angles, the strong influence of the number of layers on deformation behavior was observed. The existence of few support points in the one-layer 3D lattice core designs led, with positive or neutral cell angles, to the perforation of the top surface. On the other hand, auxetic cells prevented perforation and cracking even in one-layer designs due to the build-up of additional compressive stresses in the upper cover surface during deformation.