3. INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE, MECHANICAL AND AUTOMOTIVE ENGINEERINGS AND TECHNOLOGY IN TURKEY, Nevşehir, Türkiye, 24 - 26 Haziran 2020, ss.396
Providing lifting in aircraft is as a result of either fixed or rotary wings. When the aircraft uses rotary wings to provide lifting, this is called rotorcraft and this system can be seen in helicopters, autogyro, gyrodyne systems, etc. Helicopters which are the main topic of this study are mostly used for search&rescue, transportation, and military purposes. To fulfill these purposes, in the design process of the helicopters, their rotor parts must be designed in a variety of ways such as in the form of tandem rotors, coaxial rotors and etc. Generally, helicopters have either one or two rotors and this two-rotor system mainly consists of the main rotor and tail rotor. The main rotor system could be also categorized as a semi-rigid main rotor system, rigid main rotor system, and fully articulated main rotor system. A fully articulated main rotor system allows each helicopter blade to attach the main rotor hub by hinge/hinges which let/lets the blade flap up and down, feather, and lead/lag independently of each other. Basically fully articulated main rotor systems consist of blades, main rotor hub, elastomeric bearings, retention links, pitch links, and swashplate mechanism. Nowadays Turkish Aerospace, Bell, Agusta Westland, and Sikorsky Helicopters utilize fully articulated rotor systems. In this study, titanium/steel alloys and composite main rotor hubs are designed for a fully articulated main rotor system to investigate the mechanical strength of the main rotor hub to discuss the critical area of the whole system. This is a result of weight reduction concerns. For that purpose, static analysis is made by using the finite element method package program “ABAQUS” to find out critical stress regions under maximum flying loads and the analysis results are compared in terms of weight and strength.