Experiment and Numerical Study on the Dynamic Response of Foam Sandwich Panels under the Near-Field Blast Loading

Abstract

Aiming at the problem that the blast load, generated by the explosion of the tandem-shaped-charge warhead, may cause damage to the warhead structure, material failure and even phase change, the material damage and structural protective capacity of the near-field blast load on the sandwich structure with foam-aluminum core were investigated by experimental test and numerical simulation. Firstly, the near-field blast test was performed to observe the deformation of sandwich structure and to collect the acceleration signals of fuze. Then, the mechanical properties of foam materials were tested, and a numerical model of blast load environment was established in the explicit dynamics software ANSYS/LS–DYNA 2020 R2. Finally, the experimental test data and simulation results were compared and analyzed. The strong agreement between the experiment and the simulation results indicates that the calculation method and simulation model are reasonable. Furthermore, the damage mode of foam-aluminum core materials with different densities and cell diameters under near-field blast load were carefully analyzed by simulation method. The simulation results show that, with the decrease of the density of foam-aluminum material and the increase of the cell chamber diameter, the deformation of the foam-aluminum panel gradually increases; the acceleration peak value of the fuze gradually decreases, and the pulse width barely changes and remains basically constant; the start and end times of the peak stress of the fuze cover gradually lag behind, and the peak stress hold-up time increases gradually; the maximum displacement deformation of the fuze cover decreases firstly and then increases. This work is expected to provide basic data and design guidelines for the graded foam sandwich panels of the blasting warhead fuze against the near-field blast load.