RESEARCH ON DYNAMIC CRUSHING AND MECHANISM OF MITIGATION AND ENERGY ABSORPTION OF CELLULAR SACRIFICIAL LAYERS

In this paper, the dynamic crushing behavior and the mechanism of mitigation and energy absorption of the cellular sacrificial layers subjected to the intensive dynamic loading are investigated theoretically and numerically. Based on the rigid, perfectly plastic, locking (R-PP-L) and the rigid, plastic hardening (R-PH) constitutive models of the cellular materials, a theoretical model of the dynamic response of the cellular sacrificial layers subjected to the intensive dynamic loading is developed. The one-dimensional shock wave propagation in the cellular sacrificial layers is analyzed further. Finite element model is established by employing the Voronoi method and the numerical simulations are carried out to obtain the deformation modes and the response curves whilst the effect of interface on the mitigation and the energy absorption of the cellular sacrificial layers is discussed in detail. It is shown that the theoretical model considering the plastic hardening of cellular materials (R-PH model) can effectively predict the reflection of incident wave at the distal end and the secondary compression process of the cellular sacrificial layers as well as the enhancement phenomenon of the end stress than the R-PP-L model. Comparisons between the continuous and discontinuous interface models demonstrate that the continuous design of the cellular sacrificial layers can enhance the mitigation and the energy absorption while the interfaces separated by the rigid plates can decrease the effect of the incompleteness of interface cells. The peak stresses at the ends subjected to the same momentum increase with the increase of impact energy. It is possible that the reflection of the shock wave at the ends results in the stress enhancement at the ends.