Structural Optimization Design And Dynamic Analysis Of Hingeless Rotor Model

The rotor system, which is the key distinction between helicopter and fixed-wing aircraft, is one ofthe most important parts in helicopter. With the use of advance material, there’s an extremely rapiddevelopment in helicopter, especially in the improvement of rotor system. The hingeless rotor has gotan extensive development since1970s. The flap hinges and lag hinges are removed but not thefeathering hinges in hingeless rotor helicopters. The blade movement is implemented by thedeformation of flexible beam. Thus, the design of composite flexible beams is one of the keytechnology of hingeless rotor system.In this paper, the dynamic optimization for composite flexible beams of hingeless rotor arestudied, and the key technology of the dynamic optimization are analyzed. The main research work ofthe thesis is given as follows:(1)Based on the theory, VABS (Variational asymptotical beam section analysis method), thecalculation process and program for the analysis of composite beam’s sectional properties is set up,and the correctness and effectiveness are verified by calculating examples. By researching the processand method of integrating Isight VABS and matlab, the topology shape of flexible beam is calculated.The process uses different optimization method to get the different topology shapes.(2)Based on sectional parametrical modeling of the composite flexible beam, the program forsectional parametrical modeling of flexible beam and automatic meshing is prepared. By using theoptimization software, the size optimization of flexible beam’s topology shape is conducted. Takingthe laminated composite beam as an example, the effects of the sectional stiffness characteristics,which are caused by the ply angle, layer rules and the size, are analyzed.(3) The general structural parameters, the layouts forms and the material parameters of hinglessrotor system are determined, and the three dimensional model and assembly model are finished byCATIA on the basis of the above parameters.(4)By using Ansys Workbench, the inherent characteristics of blade are analyzed, the first threeflap, first two lag and first twist frequencies and modal shapes are obtained, and the resonance graphof the blade is drawn. The resonance graph proves that the rotor model of this paper can meet thedynamic requirement.