Models for Momentum of Debris Cloud and Ejecta Produced by Hypervelocity Impacts of Aluminum Spheres with Thin Aluminum Sheets

Debris clouds produced by the normal impact of an aluminum alloy sphere with an aluminum alloy sheet can scatter flying downrange, as well as an ejecta veil is produced at the same time. The momentum of debris clouds and ejecta are necessary to create the debris clouds and ejecta theoretical models. 54 numerical simulations were performed using the SPH (smoothed particle hydrodynamics) technique in AUTODYN-2D, in which 6.35 mm diameter of 1100-O aluminum spheres impacted six thicknesses of 6061-T6 aluminum sheets at velocities ranging from 1.0 km/s to 5.0 km/s. Using the data from the numerical simulations, two respective regression models are developed for characterizing the momentum of debris clouds and ejecta produced by impacts with 1.0 km/sv5.0 km/s, 0.5 mm3.0 mm. In the two models, the independent variables are the impact velocity, v, and the thickness of the sphere, t, while the dependent variables are the momentum ratios (ratios of debris clouds momentum and ejecta momentum to sphere momentum). The effects of v and on the momentum of debris clouds and ejecta are investigated. Seven additional numerical simulations in the same way as above were carried out and values obtained are compared with the experimental data of NASA to evaluate the performance of the simulation.