Parametric study of an elliptical fuselage made of a sandwich composite structure

摘要

We size the shell thickness of a pressurised elliptical fuselage and analyse the weight gains or savings compared to a circular fuselage. Three fuselage construction cases are analysed: a monolithic construction, a symmetric sandwich with two facesheets of equal thicknesses separated by a lightweight core, and an unsymmetric sandwich with two facesheets of different thicknesses. We develop a proper dimensionless analysis comparing the proposed elliptical fuselage with a circular one for two different scenarios: equivalent cross-section areas and enclosing a similar rectangular box. We apply a semi-analytical thin shell theory to compute the loading due to pressurisation around the circumference of the fuselage cross-section. We select the facesheet thicknesses above and below the sandwich core at every location to minimise weight. The goal is to compute the structural weight gain or penalty that is incurred by replacing a circular fuselage with an elliptical one to resist internal pressurisation in function of the scenario, eccentricity, fuselage diameter, and sandwich core thickness. We find that an elliptical cross-section incurs a significant penalty in terms of necessary facesheet thickness even with an optimised unsymmetric sandwich construction. This penalty can be minimised by keeping the eccentricity low, the loading intensity low and the core thick. (C) 2015 Elsevier Ltd. All rights reserved.