Designing and FEM simulation of the helicopter rotor and hub

Abstract

The paper presents a preliminary design of the three-blade rotor. The geometric model was prepared in the Siemens NX 12.0 programme. After the preparation of the model and kinematic analysis, the structure was checked for strength by means of NX Nastran software. In addition, structural solutions of bearing rotors currently used in the construction of helicopters were discussed and a comparative analysis of the developed rotor design with other rotors was carried out in order to define the basic advantages and disadvantages of each solution. The main rotor of a helicopter is considered the most important component of the rotorcraft, which determines its performance. Rotating blades generate the resultant forces and moments in the rotor hub that allow the helicopter to fly. In the case of a single-rotor helicopter design, a tail rotor must be added to obtain directional control. Cyclic and collective control of blade inclination influences the generation of aerodynamic and inertial loads, which depend on the azimuthal position of the blade on the rotor disc. The number of rotor blades and the properties of the blade-hub connections strongly influence the level of load transfer from the blades through the hub to the helicopter fuselage. By incorporating a set of hinges, it is possible to reduce the component loads of the rotor, tilt and rolling moments transferred to the hull. A conventional articulated rotor head with built-in hinges requires frequent maintenance, which increases helicopter operating costs. Furthermore, a complex structure with a large number of components increases the weight of the articulated rotor.