Low speed impact simulation of explosive charge based on three-dimensional numerical manifold method

The present work addresses the challenge of evaluating the low speed impact response of polymer bonded explosive charges with three-dimensional numerical manifold method. Based on the cover-based contact theory, the contact algorithm is implemented by transforming position relationships between reference points a₀ and entrance block E(A, B). Meanwhile, based on statistical micro-cracks, a Visco Scram mechanical model for the explosive charge is established. Using the classic Steven test, the influence of charge thickness, diameter, and warhead shape on the mechanical response are analyzed under low speed impact. The simulation results indicate that, increasing the thickness of the charge can effectively avoid internal damage of the explosive caused by projectile extrusion and holder confinement; Increasing the aspect ratio of the charge can alleviate the large deformation; Increasing the shape and size of the warhead can make the charge extrusion shallower, alleviating the concave shear damage of the charge. The simulation results verifies that the developed contact algorithm in this paper can effectively solve 3D impact problems, and provides guidance in the design of charge structures to some extent in the weapon system.