Crashworthiness, Impact & Structural Mechanics Group
Research: Helicopter Crashworthiness
A method for modelling helicopter impact on water including cavitation and water ingression into the failing structure has been developed based on non-linear finite element - SPH coupling. The new understanding of structural response on water resulted in a new protection concept based on multiple load paths in the main energy absorbing structure. The work is being sponsored by the European Commission under the Aeronautics "Growth" Programme.
Early research focussed on the simulation of individual structural components or small sections. Examples include the collapse of a helicopter lift frame and the impact of a section of an underfloor structure on water. The pictures below show the initial and deformed shapes of this section. These simulations were limited by the computer power then available. This work was sponsored by Westland Helicopters.
Improvements in computer power and anaysis code capability now allow larger models to be practical. Under the European Project CAST (Crashworthiness of Helicopter on Water: Design of Structures using Advanced Simulation Tools) Cranfield has performed a simulation of an entire helicopter into water. This model contains over 500,000 elements and takes over two weeks on a four processor computer to run. This size of model allows all important structural components to be well resolved.
The results from this analysis have been compared with experimental results and the deformation shows good agreement. This work has been funded by the EU
A second area of research has been on improving the capability of analysis codes to model fluid-structure interaction. A method for modelling helicopter impact on water including cavitation and water ingression into the failing structure has been developed based on non-linear finite element - SPH coupling. The pictures show the impact of a subfloor section on water, where the water is represented by SPH particles.
The new understanding of structural response on water resulted in a new protection concept based on multiple load paths in the main energy absorbing structure. This work has been funded by the EU under the CAST project.
European Project CAST - Crashworthiness of Helcopter on Water: Design of Structures using Advanced Simulation Tools
