Preliminary design and analysis of crashworthy structures for a long-range eVTOL aircraft

Abstract

In aircraft structural design it is of utmost importance to minimise the structural mass while maintaining a durable structure that is able to sustain the design loads for a predetermined number of flight cycles. The present manuscript investigates a methodology for the preliminary design and analysis of a tandem-wing long-range electric vertical takeoff and landing (eVTOL) aircraft. First, a class I weight estimation for initial loads calculation is presented. Next, the flight envelope, main load cases and failure modes considered in this preliminary design are explained. Load approximations for the wing structures in cruise and take-off conditions are presented and discussed. Next, Cessna's class II semi-empirical weight estimation method is applied to calculate the mass of 11 eVTOL aircraft subsystems. A design concept for the wing tilting mechanism is proposed. Thereafter, an initial fuselage layout design is presented, followed by a discussion on design for crashworthiness. The aeroelastic behaviour of the wing and the whirl flutter considering the propeller engine structures is investigated. Lastly, refinements in the design parameterization are implemented concerning the thickness distributions in the structural elements of the wingbox, and finally a sizing of the wing rotating shaft is performed.

Preliminary performance assessment of a long-range eVTOL aircraft

“…The mass of the aircraft is estimated in the first iteration of the preliminary design using a class I method, where relationships between MTOW and EOM, and MTOW and payload mass are found from statistical data on existing eVTOL aircraft. This, however, rendered inaccurate results due to the limited data available [1,10]. Sequentially, a more accurate class II weight estimation is performed, using the method from Cessna that can be found in [11].…”

“…The battery mass is estimated based on the energy consumption during flight. Given that the energy consumption is an output of the performance analysis herein presented, an iterative procedure is needed [1,10].…”

Preliminary Design and Optimization of Primary Structures for a Tilt-Duct UAV

“…Ref. [11] has widely reviewed ducted fan research activities with a focus on ducted fan aerodynamic simulations and experiments. Ref.…”

“…As compared to other disciplinary methods, there is a relatively limited body of work in the field of structural design and optimization for tilt-duct eVTOL aircrafts. According to the knowledge of the authors, existing research related to tilt-duct eVTOLs mainly focuses on component-level structures such as the tilt-rotor wing [11,[18][19][20][21][22][23][24] and rotor blade [25].…”