Numerical Investigation of Stresses on the Composite Aircraft Fuselage

Abstract

Improvement of an aircraft’s efficiency and performance can be achieved by decreasing the aircraft weight through considerable usage of composite materials in the aircraft fuselage. Composite materials are relatively new and there is still very few research on the stress distributions of composite fuselage. This study focuses on the effects of pressure and thermal loadings on the hoop stress of a carbon fiber fuselage skin at a cruising altitude of 11,000 m through finite element simulation. Model used in this analysis consists of a quarter of the cylindrical fuselage with two window cut-outs. Analysis shows that the addition of frame onto the fuselage was able to significantly reduce the maximum stress levels by approximately 23.5% and the addition of stringers further reduced the stress levels by another 29.2%. Further analysis shows that the frame and stringers mostly reduce the hoop stresses on the fuselage that were caused by pressure loadings, whereas minimal reduction was observed for the stresses from the thermal loadings. Finally, a comparison demonstrated that an aluminum alloy fuselage would experience an approximately 221.0% increase in maximum stress at cruising altitude and a 43.0% increase in mass for the same fuselage if compared to the carbon fiber material. Nevertheless, if compared to the relative yield strength of each material, the aluminum alloy achieved a 43.0% larger safety factor than the carbon fiber material.