基于应变能理论的端齿弯曲刚度及其转子动力学特性影响研究

Research of the Bending Stiffness of Couplings and the Effect of Rotor Dynamic Characteristics Based on Strain Energy Theory

应变能理论在多载荷条件或复杂模型的弯曲刚度计算方面具有重要意义,对转子系统动力学研究也具有一定指导作用。通过燃气轮机转子轮盘端齿的几何参数关系,构建端齿的参数化模型。在此基础上采用三维有限元计算与应变能理论相结合的方法,分析了端齿的弯曲刚度特性,结果与文献中结果吻合较好。研究了端齿弯曲刚度损失比例与发生损失的位置对转子模态特性的影响规律,结果显示,随着端齿弯曲刚度损失的增大,转子临界转速呈现加速下降的趋势,且靠近转子前支点的1级端齿对转子系统刚度与模态特性的影响最大。

Strain energy theory plays an important role in the calculation of bending stiffness of multi-load condition or complex models,and also plays a guiding role in the research of rotor dynamics.A parametric model of the couplings of gas turbine was established based on the relationship of geometric parameters of the couplings.On this basis,the bending stiffness characteristics of the couplings were analyzed by three-dimensional finite element calculation combining with strain energy theory.The result is in good agreement with the results in the literature.The influence of the loss ratio of bending stiffness and the position where the loss occurred of couplings on the modal characteristics of the rotor was studied.The results show that the critical speed of rotor decreases rapidly with the increase of couplings bending stiffness loss,and the first stage couplings near the rotor front bearing have the greatest influence on the stiffness and modal characteristics of the rotor.