本文用数值方法研究带裂纹Jeffcott转子的分岔与混沌振动特性。研究结果表明 ,当裂纹较深时 ,裂纹转子在参数共振转速附近存在丰富的周期、拟周期振动和混沌运动 ;裂纹转子振动进入混沌的途径主要通过二次Hopf分岔实现。这些结论 ,为旋转机械裂纹转子的诊断提供了一些有益的证据 In this paper, the bifurcation and chaotic vibration characteristics of a cracked Jeffcott rotor are studied numerically. The results show that the cracked rotor has rich periodic, quasi-periodic and chaotic motions near the resonant frequency of the crack when the crack is deep. The path of the crack rotor vibration entering the chaos is mainly achieved by the second Hopf bifurcation. These conclusions provide some useful evidence for the diagnosis of rotating mechanical crack rotor