Numerical study of the influence of interfaces between explosives and steel plates

The interface between explosives and steel plates can vary in the clearance of a gap or the presence of a cushion, and the dimension of the interface region can also differ. These variations in the types of interface may affect the dynamic loading and energy absorption of steel plates driven by detonation. To investigate this issue, we conducted a numerical study on the influence of different interface types and thicknesses. Initially, we designed a simulation model of a detonation driving a steel plate, with one half featuring clearance between the explosive and the steel, and the other half filled with a cushion. We then carried out simulations to analyze the influence of varying clearance and cushion thickness on the dynamic loading and energy absorption of the steel plate. The results indicate that a small-thickness clearance between explosive and steel can increase the kinetic energy of the steel plate, and there may be an optimal clearance thickness to maximize the energy absorption of the steel plate. As the clearance thickness is increased, the first loading pressure in the steel decreases, and the spallation and recompression processes in the steel gradually transform into an approximately uniform loading process without fracture. On the other hand, filling the clearance with a cushion has a negative effect on the energy absorption of the steel plate, and the kinetic energy of the steel plate decreases nearly linearly with an increase of the cushion thickness. As the cushion thickness is increased, the first loading pressure in the steel decreases less, and the dynamic behaviors of spallation and recompression may occur. Lastly, we briefly discuss interfaces with uneven thickness, which should be strictly controlled to prevent the occurrence of unexpected phenomena.