支承动刚度对转子系统临界转速的影响及试验验证

Influence of Dynamic Stiffness of Support on Critical Speed of Rotor System and Experimental Verification

支承动刚度对转子系统的临界转速等固有特性影响很大,但其影响规律及程度研究尚不深入,研究动刚度对临界转速的影响规律,提出用动刚度影响判断指数表征动刚度影响程度。首先,建立了考虑支承动刚度的转子系统动力学模型。然后,分析了支承动刚度对临界转速的影响及其不同参数对应的影响规律。结果表明,支承动刚度可导致临界转速降低并出现新的共振峰,且动刚度对临界转速的影响程度与初始支承刚度呈正相关,与转轴长度、转盘质量呈负相关。最后,提出了动刚度影响判断指数可用于动刚度影响程度定量表征,通过数值算例与试验研究对所提动刚度影响判断指数进行验证,数值与试验研究均验证了动刚度影响判断指数的有效性。

The dynamic stiffness of support affects the critical speed and inherent characteristics of rotor system greatly,but the research of influence law and influence degree of dynamic stiffness are not thorough.The influence law of dynamic stiffness on the critical speed is studied and the dynamic stiffness influence judgment index is proposed to represent the degree of dynamic stiffness influence.Firstly,the dynamic model of the rotor system considering the dynamic stiffness of the support is established.Then,the influence of dynamic stiffness on critical speed and its vary law under different parameters are analyzed.The dynamic stiffness of the supports may lead to the reduction of the critical speed and the emergence of a new resonance peak.The influence effect of dynamic stiffness is positively correlated with the initial support stiffness,but negatively correlated with the length of the shaft and the mass of the disk.Finally,the dynamic stiffness influence judgment index is proposed for the quantitative characterization of the dynamic stiffness impact degree,and the dynamic stiffness influence judgment index is verified by numerical examples and experimental studies.Both numerical and experimental results verify the validity of the dynamic stiffness influence judgment index.