Numerical simulation of ground impact after airdrop

The airborne forces of many countries use honeycomb paper as energy damping material (EDM) for heavy cargo airdrop. Its roughly constant crushing resistance makes the dimensioning of the kinetic energy absorber layer quite easy. Yet the velocity and attitude of a parachute at ground impact is variable, due to weather conditions, or undamped pendulum movement of the load under the parachutes. Those parameters have a big influence on the shock level generated at ground impact. Since ground and flight testing is long and expensive, the Flight Test Centre (CEV) of the French MoD has been developing simulations tools to evaluate the EDM design efficiency for all impact conditions at the rigging’s draft design level. In 2003, the CEV definitely chose LS-DYNA for that kind of simulation and proved the consistency of the results for Shock Response Spectrum (SRC) prediction and comparison. The paper presents the modelling work made for the EDM an application results for ammunition and vehicle airdrop.