Crashworthiness of the Flying-V Aircraft Concept with Vertical Drop Test Simulations

Abstract

The following presents a preliminary assessment on the crash characteristics of the Flying-V aircraft, an unconventional configuration consisting of a V-shaped flying wing with an oval cabin cross section, currently being actively researched at TU Delft. Successively, the preliminary assessment is carried out by means of design of experiments, where four crash structure concepts are defined and evaluated. Virtual drop tests of the Flying-V typical fuselage section are performed while measuring the energy absorption of the fuselage, and the dynamic response index (DRI) and selected locations. The finite element modeling scheme is validated using the Fokker F-28 Fellowship typical section, for which physical drop test data is available. While a crashworthy typical section for the Flying-V could not be designed, it has been found that a conventional crash concept with a total of four oblique floor struts is able to absorb 72% of the total kinetic energy, with a DRI reaching 18.2 units. A sensitivity analysis shows that the bending stiffness of the frames has a critical role in the crashworthiness of the Flying-V, due to the increase in rigidity following pressurization loads of the oval fuselage section and that, additionally, the structural simplifications applied in the context of the research likely rendered the results overly-conservative. A 16% frame thickness reduction resulted in a DRI of 16.2 units, just above the 16 units typically required by regulators. Recommendations for future work include a structural sizing optimization where requirements from crashworthiness and airworthiness can be evaluated simultaneously as design constraints, enabling design for crashworthiness at the preliminary design.