Examination of yawed impact using a combined numerical and analytical approach

Performing sensitivity studies using 3D-hydrocodes have normally been an extremely time consuming process and still remains so even though computer speed continues to increase. To overcome this problem, a combined analytical and numerical approach based on cavity expansion theory (CET) was implemented as a user subroutine in Autodyn-3D. This enables us to model only the projectile explicitly, whereas the response of the target is incorporated through analytical theory. The runtime of the problem is then reduced to less than 1% of a corresponding full 3D simulation, and makes it possible to easily perform sensitivity studies for cases of non-normal impact. This can be very useful before full 3D-simulations are performed, or in its own right. As an example of use, a parameter study of yawed impact has been performed for two different projectiles at different velocities. This was completed in a few hours whereas a corresponding full Autodyn-3D study would have taken many weeks.