TRANSIENT THREE DIMENSIONAL FINITE ELEMENT ANALYSIS OF A BIRD STRIKING A SANDWICH TAILPLANE LEADING EDGE

Aircraft leading edges must be certified for a proven level of bird impact resistance. In particular, the main structural requirements is to protect the torsion box and control devices from any significant damage caused by birdstrike in order to allow the aircraft to land safely. Since the experimental tests are expensive and difficult to perform, a significant help in designing highefficiency bird-proof structures can be provided by numerical tools. The aim of this research paper was to design a ribless sandwich leading edge capable of withstanding birdstrike by employing state-of-the-art numerical simulations in order to reduce development costs. The material considered was a sandwich structure made up of fiber metal laminate (FML) skins and flexcore as core. Pre-test numerical simulations of birdstrike impact were performed adopting a lagrangian approach to design the ribless fin leading edge. The final design was tested under the conditions specified by the Federal Aviation Regulations. The numerical and experimental correlation showed good results both in terms of global deformation and impact behavior of the test article confirming the capability of the proposed numerical approach to design FML bird impact resistant leading edges.