A 3-node Shaft Element for Main Shaft Vibration FE Analysis

To calculate the characteristics of the lateral vibration in the main shaft system of the hydro-turbine generating set, a three-node elastic shaft element was proposed. Its dynamic equation was derived and the interpolation function, translational inertia matrix, rotational inertia matrix, gyroscopic matrix and the stiffness matrix were obtained. Based on Matlab platform, a FEM program was developed for calculation and its correctness was verified through a numerical example. The study shows that, compared with the method using two-node shaft element, the results of the three-node shaft element are closer to the theoretical solution and the accuracy is higher.