Numerical Simulation of the Fragmentation Process of High Explosive Projectiles

 

Marinko Ugrčić

 

 

The latest computational techniques, based on the finite element method (FEM), are developed to solve explicite dynamics problems and can be applied for the prediction of natural fragmentation of high explosive (HE) projectiles. The new methodology for numerical simulating performances of projectiles fragmentation integrates the FEM and the stochastic failure theory in the ANSYS AUTODYN^® solver for two- and three-dimensional axis-symmetric analyses of the fragmentation process. This paper presents the results of the numerical analyses of the characteristics of fragmentation in terms of initial velocities, spray angle, fragment length and fragment mass distributions of a 105 mm HE projectile. The projectile fragmentation parameters depend on the projectile shape and size,casing thickness, explosive type, detonator size and position, etc. This paper focuses on the effects of the mechanical properties of the projectile casing material and the explosive type on the fragmentation characteristics. It was confirmed that the mechanical properties of the casing material have low effects on the initial velocities of fragments. Moreover, it was shown that a brittle casing material with low failure strain tends to produce a higher number of fragments with less average fragment mass. The comparison with some experimental data confirmed that the computed parameters of fragmentation predict properly the characteristics of casing disruption.

Key words: high explosive projectile, projectile fragmentation, 105mm caliber, numerical simulation, finite element method.