Non-Structural Mass Modeling in Aircraft Impact Analysis using Smooth Particle Hydrodynamics

The non-structural mass in the large commercial airliners includes fuel, cargo, passengers, luggage, seats, lockers, etc. The straightforward approach for modelling of this non-structural mass is to include it as additional mass density to the corresponding structural elements. This approach would lead to conservative results in case of impact as the non-structural mass remains attached to the aircraft for the entire duration of the calculation, resulting into an overestimated impact effects. Alternative approach for modelling of non-structural mass is the application of the Smooth Particle Hydrodynamics (SPH) method. For the purposes of the current study two models of the aircraft B777 are created: in the first model the non-structural mass is considered as additional mass density and in the second model the entire non-structural mass is modelled with SPH. Simulations of aircraft impact into rigid wall have been performed. The crushing pattern of the plane and the impact forces corresponding to the two models are compared. The impact forces obtained by the calculations are compared to the ones obtained by the Riera method. Additionally, the influence of different analysis parameters such as friction between SPH and airplane and type of equation of state (EOS) has been investigated.