Clean Sky 2 Deliverable D1.4.1.3-12 - Impact test and design update finalized

Abstract

The report summarises the design update realised on a reduced size leading edge demonstrator segment. This segment represents the dimensions of a horizontal stabiliser leading edge at outer span width of a long range aircraft. The given segment includes an HLFC technology by a multi-chambered suction system with a micro-perforated outer skin. The design update was performed in terms of composite layup and manufacturing plus assembly with the micro-perforated titanium skin. The design and manufacturing processes were accompanied by numerical simulation with respect to impact and was concluded with an impact test similar to airworthiness regulations. The key objectives are to decrease the manufacturing time of all steps and to create an impact validation data base for the complex material set-up for HLFC. In order to improve the aero industry applicability of HLFC, the improved leading edge design was scrutinised with a relevant impact load case. Based on the certification specification along the FAA for passenger transport aircraft, the impact velocity and bird weight were chosen. This requirement was chosen since it exceeds the EASA with respect to the stabilisers. The demonstrator segment had a reduced size compared to a full leading edge segment, however it represented more than two rib bays. All constituents of the reduced size demonstrator as well as the artificial bird were modelled and calibrated in detail within numerical simulation but only reduced characterisation data for the materials were applied. The sensitivities were studied and the final impact test prepared. The post-test simulation was used to account for the impact test conditions in terms of precise attitude and speed of the impactor.