Research on the numerical method and crashworthiness of typical civil aircraft fuselage for water impact

To improve the safety of civil aircraft during emergency loading, the numerical model and impact characteristics of a typical fuselage are investigated for water impact. The finite element model of a civil aircraft is built based on sound simplification. A water model is simulated by Finite Element Method (FEM), Arbitrary Lagrangian-Eulerian (ALE) and Smoothed Particle Hydrodynamics (SPH). The crashworthiness of a typical fuselage with different water materials are discussed. The vertical drop velocity of 7 m/s is adopted, and gravitational acceleration is considered. Finally, the water impact characteristics of a civil aircraft are compared with those under rigid floor impact conditions. Numerical results show that ALE is the best numerical simulation method. The crashworthiness of a civil aircraft for null material is obviously different from that of others for the lack of deviatoric stresses. The deformation of fuselage is small because most of impact kinetic energy is dissipated by water. Skin absorbs large part of impact kinetic energy because it is under large distributed impact load, and it is one of the most important energy absorption structures for water import problems. The acceleration overload with water is smaller than that with rigid floor. The impact load transferred to passengers could be improved if lake or river is chosen as a landing site.