轮盘端面齿连接的周向拉杆转子刚度研究

针对轮盘端面齿连接的周向拉杆转子模型,理论分析得到转子各组成部分刚度计算方法.应用商业有限元软件ANSYS,基于三维有限元非线性接触算法计算预紧力下轮盘端面齿连接段的弯曲刚度和扭转刚度,得到刚度修正系数和刚度无量纲系数.分析周向拉杆刚度和轮盘刚度的关系,提出拉杆刚度比例系数.计算结果表明:刚度系数无量纲系数小于1时,刚度修正系数保持不变；刚度无量纲系数大于1时,此时预紧力不足,齿面发生滑移,刚度修正系数会突然降低,拉杆弯曲刚度比例系数会增加.刚度无量纲系数具有明确的物理意义,可为带端面齿的燃气轮机转子设计和故障诊断提供参考.

Investigation on stiffness of circumferential distributed tie-rod rotor with curvic couplings of trochal disk

Based on the circumferential distributed tie-rod rotor model with curvic couplings, the stiffness of every part of the rotor was acquired with analytical method. Three-dimensional finite element nonlinear contact method was adopted to analyse the flexural stiffness and torsional stiffness of the curvic couplings after preloading by using the commercial finite element software ANSYS. The stiffness correction coefficient and stiffness nondimensional coefficient were obtained. Coefficient of tie-rod stiffness ratio was adopted to describe the relation between the stiffness of tie-rods and disks. Results show that stiffness correction coefficient keeps steady when the stiffness nondimensional coefficient is less than 1, while it drops abruptly and the coefficient of tie-rod bend stiffness ratio increases when stiffness nondimensional coefficient exceeds 1. This means the preload is not enough and slip between curvic couplings happens. Stiffness nondimensional coefficient reflects some certain stress status of the curvic couplings, providing a basic guide for design and fault diagnosis of gas turbine rotor with curvic couplings.