一种汽轮发电机组轴系扭振疲劳损伤的估算方法

A Damage Assessment Method on Torsional Vibration of Large Steam Rotors with TSR Waveform Record and FEM

采用传统轴系扭振模型对大型机组轴系扭振损伤进行评估,由于研究方法和模型简化等因素影响,导致其对轴系扭振及疲劳损伤评估的效果并不理想。通过对机头实测扭角信号进行分解,并结合全尺寸轴系有限元扭振模态分析及非线性接触和塑性分析方法,提出了一种基于实时录波数据的轴系扭振损伤评估方法,为电厂轴系扭振寿命快速、准确评估提供支持。

Based on theoretical modeling with partial differential equations or simplifying,some methods were proposed to predict the torsional vibration features of the large steam rotors. Due to inherent deficiency of this mothods, there is a disadvantage to apply them. In this paper, a study on the method which can be used to assess fatigue damage of turbine shafts was proposed based on the TSR waveform record and full-size FEM. In this method, the modal vibration shapes of turbine shaft were obtained by using full-size 3D FEM model, and the load spectrum of fatigue dangerous position were obtained by using modal decomposition. The results provide a better choice for the torsional fatigue damage both for on-line and off-line situation.