Oblique impact modeling of fuzes

This paper presents the results of a combined experimental, numerical, and analytical investigation of a low-speed (198 m/s) oblique impact of a cylindrical steel projectile into an aluminum-brass composite fuze simulant. The numerical simulations were performed prior to the experiments using the Lagrangian hydrocode EPIC92. The results indicate that projectile hardness and impact point strongly influence the mechanism by which the fuze deforms. An experiment was then conducted in order to evaluate the predictive capabilities of the hydrocode. The experimental results generally corroborate the hydrocode results during the initial stages of the impact but depart significantly at later stages of the penetration. Possible causes for the observed differences between the experiment and the simulation include, (i) the absence of a global fracture modeling capability in the hydrocode, and (ii) boundary condition differences between experiment and simulation. The hydrocode predicts that 91% of the projectile kinetic energy is converted into target plastic work. This result compares well with predictions based upon an analytical model of an elastic-plastic beam bent by an end load.

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