SURVEY OF FEASIBLE NUMERICAL APPROACHES TO ANALYSE THE BEHAVIOUR OF A COMPOSITE SKIN PANEL DURING A WATER IMPACT

摘要

Water impacts are likely to have tragic consequences for the passengers of helicopters. Most of the passive safety devices developed for helicopter crashworthiness are designed for ground impact. When impacting a solid or a soft surface, impact loads are rather different and therefore energy absorption devices developed for ground impact are not effective during a water impact.In order to collect reliable data for numerical model validation, water impact drop tests were carried out: a Carbon Fiber Reinforced Plastic panel, similar to modern aircraft skin panels, was mounted on a specific test device and tested. Impact decelerations and deformations of the panels were measured. Afterwards, numerical models of the tests were created. Finite element and meshless approaches were used to model the water region. Eventually, a close experimental-numerical correlation was obtained for each model in terms of impact dynamics, decelerations and deformations. The main features of the event and the differences between the four numerical approaches were discussed. Guidelines for further investigations were also drawn.