摩擦传递扭矩的大型旋转机械主轴强度分析

Strength Analysis of Spindles of Heavy-Duty Rotary Machines with Friction-Type Torque Transmission

承受外载的旋转机械靠摩擦传递扭矩时,主轴属于三维材料非线性与边界非线性的耦合问题——弹塑性接触问题。本文采用有限元增量法对此进行了详细分析,导出了基于流动理论的塑性增量的本构方程及等强化材料在复杂应力状态下的Mises模型的本构矩阵。在有限元计算中采用了精度较高的一阶自校正法,在接触问题分析中设定了自由、粘连、滑动三种边界,并采用了接触单元处理,求解时采用凝缩矩阵法及有限元混合法。对摩擦传递扭矩的水轮机主轴计算结果进行了分析,并与三维光弹实验结果进行了比较,两者是一致的。

The spindle of a rotary machine with friction-type torque transmission under external loads is of the elasto-plastic contact problem in strength analysis. Based on FEM and plastic increment in flow theory, a constitutive equation is derived, as well as a constitutive matrix of Mises model for uniform-strength materials under the action of complex stress. In FEM calculation an accurate method of first order self-correction is introduced, in contact analysis three boundaries (i.e., the free, adherent and sliding boundaries) with contact elements applied to are set up. The method of condensed matrix in association with FEM is used to solve the equation. The calculation results of the spindle of hydroturbine with friction-type torque transmission are discussed in comparison with the results obtained from 3-dimensional photo-elastic experiments. They are in conformity to each other.