Crashworthiness of a twin-walled fuselage design

Abstract

Sandwich structures consisting of thin stiff facesheets and a thick, low density core exhibit excellent stiffness-to-weight ratio and are investigated for novel light weight fuselage concepts. Currently the application of sandwich structures in transport aircraft is limited to secondary structures, since further understanding is required in the field of manufacturing, repair, vulnerability and safety before sandwich design can be applied for primary structures. Folded cores are currently investigated for future fuselage applications since the open cellular design of foldcore cells would solve the problem of humidity accumulation of closed cellular sandwich cores such as honeycombs. For novel fuselage concepts safety regulations require an equivalent crashworthiness compared to the conventional metal fuselage design. Brittle failure mechanisms of CFRP structures make the verification of equivalent crashworthiness for CFRP fuselage concepts challenging since conventional metal fuselages absorb a significant portion of the kinetic energy by plasticization.