中文摘要：

为了研究裂纹-碰摩耦合故障的一类初弯曲转子系统响应特性,在考虑转轴变形、非线性油膜力与碰摩力作用的基础上,结合由中性轴理论确定的裂纹开闭规律,建立该类故障转子的动力学方程,利用Poincaré截面和分岔图的变化分析初始弯曲程度与裂纹深度对系统振动响应特性的影响.结果表明：含初弯曲时系统振动响应在临界转速附近的混沌区域比无初弯曲时大,随着裂纹深度的增加,混沌区域逐渐缩小;初始弯曲的运动特性在浅裂纹情况下起主导作用,当裂纹深度较大时,系统振动响应随着初始弯曲程度的增大交替出现由周期演变为混沌状态的过程,混沌响应特性也可发生较大变化.

英文摘要：

To investigate the vibration response of a rotor with initial bend deformation under coupling faults of crack and rub-impact, the dynamic model of the rotor was established based on the switching regularity of the crack from the neutral axis theory, where the nonlinear oil-film force and the rub-impact force were taken into account, and the effects of the depth of crack and the degree of initial bend deformation on the vibration response of the rotor were discussed by the Poincar6＇s cross-section and the bifurcation diagrams. The results indicate that, the chaotic region near the critical speed of the rotor with initial bend deformation is wider than that without initial bend deformation, and the chaotic region will reduce gradually as the depth of crack increases. Moreover, the motion characteristics of initial bend deformation play a dominant role in the case of shallow cracks, however, if the crack is relatively deep, the periodic and chaotic states alternate with each other as the degree of the initial bend deformation increases, and the characteristic of the chaotic response may also vary from the degree of the initial bend deformation.