Fatigue analysis and design optimization of aircraft's central fuselage

Abstract

The centre fuselage of an aircraft plays a very crucial role as most of the important parts such as the front fuselage, aft fuselage and the wings are connected to it. So any load applied on these parts will be transferred to the centre fuselage. Hence it was essential to study the centre fuselage briefly in order to attain high design safety. Fatigue is the process of repeated cyclic loading of a component, which leads to an early failure of the same. The sources of fatigue in an aircraft are the parts connected to it, such as the wings, and the differential pressure between the inside of the fuselage and the outside atmosphere as a result of cabin pressurization. The high pressure inside the fuselage tries to expand the fuselage, whereas the stringers and bulk head prevent it from happening. This change in pressure happens frequently and this results in the fatigue of the centre fuselage. The vibratory loads acting on the other parts are transferred to the centre fuselage, which are also major contributors to the fatigue. The centre fuselage of an aircraft was designed using Pro-E software. The standard aluminium alloy was selected for the material. The various loads acting on the centre fuselage were studied and added to the centre fuselage, along with a differential pressure in a cyclic manner.