The vertical drop water impact of civil aircraft fuselage structure based on SPH and ALE methods

To better understand the structural response of civil aircraft, the vertical drop test of civil aircraft water impact is investigated. Finite element model of typical civil aircraft is built based on rational simplifications and physical phenomenon. Smooth Particle Hydrodynamics (SPH) and Arbitrary Lagrange Euler (ALE) are chosen as the numerical simulation methods. NULL material model with polynomial state of equation is adopted. Numerical results show that ALE method has better computational efficiency than that of SPH method. Aircraft skin plays a very important role in water impact event, while the deformation of frame is relatively small. Water would act as cushioning, and it could dissipate most part of impact kinetic energy. Elastic deformation of aircraft is the dominant deformation during water impact process. The impact force transmitted to occupant is relatively small. The crashworthiness under water impact condition is better than that of rigid floor situation.