Abstract
A 3-dimensional finite element model (FEM) for vibration analysis of steam turbine blades is presented in this paper, employing a 3-dimensional incompatible solid element with 8 nodes for overcoming over-stiffening effect of the 8-node iso-parametric solid element. A skew coordinate system is introduced in the model for considering a cyclic symmetry of displacement constraints of blades. The vibration characteristics of a 4-blade group are analyzed using the proposed FEM. A running blade vibration test has been performed to measure natural frequencies of the blade group. The analysis results show a good agreement with measurements of the vibration test, and demonstrate that the proposed method is valid and effective for the blade vibration analysis.
