Validation of Crashworthiness Simulation and Design Methods by Testing of a Scaled Composite Helicopter Frame Section

Modern helicopters make extensive use of composite materials to reduce structural weight. These include in-crash energy absorption devices integrated into the subfloor. Despite significant advances in computer-based design tools, the design of a composite energy absorbing structure is normally performed by semi-empirical methods supported by extensive testing. This paper describes the results of a project to develop improved methods for the design of composite energy absorbing structures. A building block approach was used in which, as specimens of increasing complexity were tested, simulation methods were developed and validated. These tests ranged from material characterisation through to large scale crash testing. Final validation of the simulation methods through the design and test of a representative helicopter frame section is described in detail. The results showed that the methods can be used to design a complex composite energy absorbing structure, and that they have the potential to enable improved designs, while significantly reducing physical testing requirements.