摘要
为计算水轮发电机组轴系的横向自振特性,提出了一种三结点弹性轴段单元。将主轴系统离散为刚性圆盘和三结点弹性轴段单元,推导了刚性圆盘单元和弹性轴段单元的运动方程,得出了三结点弹性轴段单元的插值函数、移动惯性矩阵、转动惯性矩阵、回转矩阵和刚度矩阵。研制了基于Matlab的有限元计算程序,并用数值算例验证了程序的正确性。最后计算了某水轮发电机组主轴系统考虑陀螺效应时的涡动频率、临界转速和相应的振型。研究表明,三结点弹性轴段单元的计算结果比二结点单元更接近理论解。
In order to analyze the characteristics of the hydroturbine generating set, a 3-node element method was presented for the elastic shaft. The main shaft system was discrete to be a rigid disk and a 3-node element, then the dynamic equations were set up derived from Lagrange equations. The corresponding interpolation function, translational inertia matrix, rotational inertia matrix,gyroscopic matrix and the stiffness matrix were also calculated. A Matlab-based FEM program was developed and verified by a numerical example. Furthermore, the whirl frequency, critical rotation of the speed and mode shape were calculated for the main shaft system when the gyroscopic effect was considered.The study shows that the 3-node element method is closer to the analytical solution than that of 2-node element.
出处
《机械设计》
CSCD
北大核心
2014年第12期98-104,共7页
Journal of Machine Design
基金
国家自然科学基金重点资助项目(50839003
51279071)
云南省自然科学基金资助项目(2008GA027)
2013年云南省博士研究生学术新人奖资助项目
关键词
水轮发电机组
轴系
三结点单元
涡动频率
振型
hydro-turbine generating set
main shaft system
three-node element
whirl frequency
mode shape
