Study On The Structure Design Of A Rigid Rotor

With the rapid development of the technologies of designing and manufacturing, more and morerigid rotors have being widely used on helicopters. So，there is an increasing demand for blades withbetter performance. Rigid rotors are thought of better solutions of speed-variable and long-endurancehelicopters and composite helicopter rotor technology for their significant abilities of improvinghigh-speed helicopters’ flight performance, maneuverability and stability. This thesis designs a rigidrotor and makes a simple analysis for its dynamic characteristics. Then, a system is designed,including a rigid blade, a hub and some other necessary parts according to the initial givenrequirements.The main work of this thesis includes the following parts:(1) The characteristics of profiles andthe influences of parameters of the profile sections are analyzed with VABS after theoretical analysis.(2) According to the results, the detail structures of a rigid blade are designed and the dynamiccharacteristics of the blade are analyzed by the three-dimensional finite element method. Further,some key components and parts’ strength is checked.(3) The accuracy of the three-dimensional finiteelement method used for the rigid rotor’s design and analysis is verified through comparison with theconventional method and blade tests of both methods on an example blade. Then optimization work isdone to the analysis method according to the comparison between analysis and tests’ results.(4) Thehub matching with the rigid rotor is designed and its strength is checked. Then, its structures areoptimized under the condition that they meet the strength requirements.Based on the beam theory, a rotor system is designed using finite element software. It including arigid blade, a hub and some other necessary parts. Its ratio of first natural frequency of flap motion isabove1.3and ratio of first natural frequency of lag motion is above1.4, which fulfils initial givenrequirements. A hub system is designed with less weight and more simple structures. At last, somekey components and profiles sections’ strength is checked. The results all meet the strengthrequirements.