Abstract <p>A Semi Reentrant structure is a hybrid structure combining standard honeycomb cells with Reentrant cells. It exhibits monoclastic curvature when bending over the vertical arm direction. The&#xa0;bending behaviours (the minimum curvature radius, <i>r</i>_min) and impact performance (peak force, maximum displacement, energy absorption and specific energy absorption) of Honeycomb, Reentrant and Semi Reentrant sandwich panels have been studied and compared via finite element simulation. The result shows that the Semi Reentrant sandwich have better bending performance and median impact properties, therefore more advantages in engineering applications. The influence of the element types of core structures and face sheet thickness on the mechanical properties of Semi Reentrant sandwich structures was investigated. With increased face sheet thickness, the <i>r</i>_min and impact strength of the sandwich structures increased with smaller peak force and max displacement. The multilayer sandwich structures with Semi Reentrant core were designed and analysed, which had the advantage of lightweight and enhancement of the mechanical properties. Finally, by filling crushable foam materials in the sandwich structures, its mechanical properties during bending and impact processes could be improved further.</p>