Crashworthiness assessment in aircraft ditching incidents

In this paper, a comparative study has been performed between the Meshless Lagrangian and Coupled Lagrangian-Eulerian schemes, to evaluate their overall efficiency and effectiveness for analyzing fluid-structure interactive systems. Soft body impact events onto composite laminates representing primary and secondary aircraft structures have been studied.Several cases with different bird velocities have been simulated to observe the non-linier behavior of soft body impact,along with the shortcomings of the modeling methodologies applied. The Meshless Lagrangian model produced a higher initial peak force, whereas the Coupled Lagrangian- Eulerian approach captured the impact window more smoothly with less obvious spikes. These schemes have also been compared with the conventional Lagrangian approach, which proved to be less accurate due to high mesh distortion and loss of mass from erosion. The study was further extended to analyze birdstrike ona composite wing leading-edge. With validation from experimental results, the developed modeling methodology was also used to analyze other fluid-structure interactive systems such as structural damage caused by aircraft ditching over water.