Dynamic response of bi-directional gradient sandwich circular plates under multiple explosive loading.

Due to its advantages in terms of enhancing the performance of structures in the applications, the gradient design has recently attracted the interest of researchers in a number of engineering disciplines. A bionic bi-directional gradient sandwich model was established inspired by the Royal Water Lily venation structure. Four sandwich circular plate models with different gradient arrangements were constructed by adjusting cell wall thickness. The deformation modes, deflections of the face sheets, and energy absorption characteristics were analyzed under multiple explosions with different blast impulses. The results indicated that the deformation of the structure and the energy absorption values accumulated progressively under multiple blast loading. However, the incremental energy absorption of both the face sheets and the honeycomb core decreases as the number of explosions increases. Compared with a single explosion, the dynamic response of models can be effectively improved by changing its gradient arrangement without adding additional mass under the multiple blast loads. Besides, the model's blast resistance remained largely unchanged, while its energy absorption capacity was significantly enhanced by 29.92% after the thickness of the front panel was reduced. Such results provide guidance for the design of bi-directional gradient sandwich circular plate under multiple blast loads.