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考虑直升机旋翼旋转时声场、应力刚化、几何大变形等复合运行环境,对多种影响因素下的旋翼动力特性进行研究。通过实验测试数据建立了直升机旋翼结构的动力有限元模型,对旋翼在静止、应力刚化影响下的动力特性进行了分析;建立旋翼声振耦合动力学模型,考虑外声场和旋翼几何非线性影响因素,深入研究旋翼动力特性的变化规律,分析了其内在机理。研究分析发现:考虑声场影响后结构前三阶的固有频率误差分别减小了0.46%、0.82%、0.45%,更接近实验值,旋翼桨叶的振幅峰值明显降低;应力刚化对旋翼模态影响较大,随着其转速的增加固有频率呈二次曲线上升趋势;几何非线性使旋翼的共振频率值略微增大、振幅极值减小。
Considering the complex operating environment such as sound field, stress stiffening and big deformation of helicopter rotor rotation, the rotor dynamic characteristics under various influence factors are studied. The dynamic finite element model of the helicopter rotor structure is established through the experimental test data. The dynamic characteristics of the rotor under the influence of static and stress stiffening are analyzed. The coupled dynamic model of the rotor is established, considering the influence of the external acoustic field and the rotor geometry nonlinearity Factors, in-depth study of the rotor dynamics characteristics of the law of change, analyzed its intrinsic mechanism. The results show that the natural frequency errors of the first three orders of the structure decrease by 0.46%, 0.82% and 0.45% respectively, which are closer to the experimental values. The peak amplitude of the rotor blade obviously decreases. The stress stiffening affects the rotor mode And its natural frequency increases with the increase of rotating speed. The geometric nonlinearity makes the resonance frequency of the rotor slightly increase and its amplitude decreases.