弹性环配合紧度对转子动力学特性的影响

Dynamic Characteristics Analysis of Rotor System with Fitting Tightness of Elastic Ring Support Structure

弹性环式支承结构作为航空发动机中典型的弹性支承结构,其配合紧度很大程度上影响支承系统的刚度,进一步影响转子系统动力学特性,但相关研究尚少。因此,首先建立了弹性环式支承结构的有限元模型,分析了配合紧度对其刚度及强度特性的影响,并发现可通过分段刚度出现时的位移与凸台高度之间的关系来判断弹性环式式支承结构的配合紧度,然后搭建了相关实验台与测试结果对比,验证了仿真结果的正确性,最后建立了考虑弹性环式支承结构配合紧度的转子系统有限元模型,研究了其对转子系统动力学特性的影响。研究表明:过盈配合下的弹性环式支承结构会导致转子系统临界转速升高,间隙配合会导致临界转速降低,并会引起转子系统非线性振动,研究结果可为采用弹性环式支承结构的转子支承系统设计提供理论参考。

As the typical elastic support structure in aeroengine,the fitting tightness of elastic ring support structure greatly affects the stiffness of the support system,and further affects the dynamic characteristics of the rotor system,but there are few relevant researches.Therefore,the finite element model of elastic ring support structure is established firstly,and the influence of fitting tightness on its stiffness and strength is analyzed.It is found that the fitting tightness of the elastic ring support structure can be judged by the relationship between the displacement when the segment stiffness appears and the height of the boss.Then carry out the relevant experimental platform.The correctness of the simulation results are verified by comparing with the experimental results.Finally,the finite element model of rotor system considering the fitting mode of the elastic ring supporting structure is established,and the influence of the model on the characteristics of the rotor system dynamics is studied.The results show that the elastic ring support structure with interference fit will increase the critical speed of the rotor system,while the clearance fit will decrease the critical speed,and cause nonlinear vibration of the rotor system.The research results can provide theoretical reference for the design of the rotor support system with elastic ring support structure.