It is well known that the interaction between the shaft torsion and the blade vibration (zero nodal diameter k=0) caused blade failure trouble in the 1985 Taiwan incident at the L-0 stage of a turbine-generator set. Recently, additional attention has been given to the coupling effect between the shaft bending vibration and the blade vibration (k=1). The following two topics are included in this paper. (1) A shaft system surrounded with 8 simple blades is offered for our study. These blades are equivalently reduced to 1 dof (a mass-spring system) by using the mode synthesis technique. Eigenvalue analysis, using this reduced model, provides two specified resonance conditions; rotational speed Ω{sub}1=|ω{sub}s-ω{sub}b| and Ω{sub}2=|ω{sub}s+ω{sub}b|, where ω{sub}s and ω{sub}b are uncoupled shaft and blade natural frequencies, respectively. The latter resonance would be more severe than the former. (2) This 1 dof blade modeling technique is generalized to obtain the equivalent blade system which is applied to actual turbine blades. This equivalent model is connected with the rotor shafting system for evaluating the coupling effect using rotordynamics calculation codes.
展开▼
机译：众所周知，轴扭转与叶片振动之间的相互作用（零节点直径k = 0）在1985年的台湾入射时引起了涡轮发电机组的L-0级的1985台的叶片故障问题。最近，已经对轴弯曲振动和叶片振动（k = 1）之间的耦合效果进行了额外的注意。本文包含以下两个主题。 （1）为我们的研究提供了一个带有8个简单刀片的轴系统。通过使用模式合成技术等效地将这些刀片等效减少到1 DOF（质量弹簧系统）。特征值分析，使用这种缩小模型，提供了两个指定的共振条件;转速Ω{sub} 1 = |ω{sub} s-ω{sub} b | ω{sub} 2 = |ω{sub} s +ω{sub} b |，其中ω{sub} s和ω{sub} b分别是轴和叶片自然频率。后一个共振比前者更严重。 （2）推广该1 DOF叶片建模技术以获得应用于实际涡轮叶片的等效刀片系统。该等效模型与转子轴系系统连接，用于使用旋转动力学计算代码评估耦合效果。
展开▼
