转轴上裂纹开闭模型的研究

本文提出了一种新的描述转轴裂纹开闭状态的数学模型,此模型描述了裂纹开、闭及过渡状态的持续过程,它将开裂纹、方波和余弦模型统一于同一模型中,它的使用不受动、静挠度关系的限制.用这个模型算得的裂纹轴刚度变化曲线与实验结果吻合程度比余弦和方波模型好.文中还以Jeffcott裂纹转子为例,对各模型进行了理论探讨.结果表明:当研究非同步运动时,本文模型与方波和余弦模型所得的解差别较大,且轴心位移矢量的方向角在静平衡位置处的波动,影响到所得响应的特性.而对同步运动,这种差别及影响都很小.

Study on the Model of the Shaft Crac Opening and Closing

In this paper, a new mathematical model of the shaft crack opening and closing is developed. In the model, the time of open close lasting and the procedure between the two states are considered. The open crack, the' square wave' and the cosine model are the particular cases of this model. This model is not limited by the relationship of dynamic deflection and static deflection when being used. The stiffness coefficients of the cracked shaft calculated with this model are more approaching the experiment results than those with the' square wave' and the cosine model. In the numerical example of Jeffcott cracked rotor, the models are used and some comparison results is given. When unsynchronous vibration being studied, the solutions of our model are quite different from those of the' square wave' and the cosine model; the change of vector direction of shaft displacement near the static balance position has some effects on the character of solution. When synchronous vibration being studied, the differences and the effects are very little.