基于虚拟材料层燃机转子接触面建模方法

Modeling method of gas turbine rotor contact surface based on virtual material layer

摘要:

为提高燃气轮机拉杆转子建模的准确性,在轮盘接触面处引入虚拟材料层对接触效应进行表征. 结合数学统计模型和高斯分布函数得到接触面接触力学模型,分析了不同参数下的接触特性,基于材料力学变形本构关系导出虚拟材料层的弹性模量及泊松比,对接触层进行建模. 动力学计算结果表明:在刚性支撑下,预紧力变化导致的接触效应对四阶临界转速的影响较为明显,转速偏差可达2.31%. 引入非线性油膜力结果表明:预紧力增大导致各运动状态提前发生,实体转子与考虑预紧力接触的转子动态结果有较大分歧. 虚拟材料层的引入有效地简化了考虑接触效应的燃机转子建模过程,并真实反映出轮盘接触效应对转子横振刚度的削弱作用.

Abstract:

To improve the accuracy of gas turbine pull-rod rotor modeling, a virtual material layer was introduced at the contact surface of the wheel to characterize the contact effect. By the mathematical statistical model and gaussian distribution function, the mechanical model of the normal contact stiffness of contact surface was obtained, and the contact characteristics under different parameters were analyzed. Based on the constitutive relation of the deformation of material mechanics, the elastic modulus and poisson′s ratio of the virtual material layer were derived, and the contact layer was modeled. The results of dynamic calculation show that, under rigid support, the contact effect caused by the change of preload has a significant influence on the fourth-order critical speed, and the speed deviation can reach 2.31%. The results of introducing nonlinear oil film force show that the increase of preloading force leads to the advance of all motion states, and the dynamic results of solid rotor and rotor considering the contact of preloading force are quite different. The introduction of virtual material layer simplifies the modeling process of gas turbine rotor considering the contact effect and reflects the weakening effect of the contact effect on the transverse vibration stiffness of the rotor.