In this study, the mechanical model of the circumferentially distributed rods and the nonlinear contact stiffness matrix which characterizes the contact effect between the disks are established. The contact stiffness matrix is composed of seven stiffness coefficients that characterize the lateral stiffness, shear stiffness, bending stiffness, and torsional stiffness of the contact interface. Then the influence of pre-tightening load, rod diameter, contact surface roughness, deformation phase and uneven pre-tightening load on stiffness coefficients is analyzed. Finally, combined with the experimentally verified nonlinear oil film force model based on short bearing theory, the dynamic model of the rod-fastening rotor-bearing system is established. By means of spectrum cascades and Campbell diagrams, the influence of the pre-tightening load, rod diameter, contact surface roughness and uneven pre-tightening load on the nonlinear dynamic characteristics of the rod-fastening rotor-bearing system is numerically analyzed. The results show that increasing the pre-tightening load can increase the contact stiffness, and make the dynamic characteristics of the rod-fastening rotor bearing system closer to that of the complete rotor bearing system. The increase in the diameters of rods significantly delay the partial separation of the contact surfaces. The smooth contact surface provides higher contact stiffness, but it is not conducive to maintaining the full contact state of the contact surfaces. The stiffness coefficients fluctuate with the deformation of the rotor, and the process is significantly affected by uneven pre-tightening load. Moreover, a self-excited vibration frequency \(f_{l}\) accompanied by a combination frequency \(f_{b} = 3f_{l}\) appears when the uneven pre-tightening load is caused by individual faulty rod. The number of rods, rod diameter, and contact surface roughness have similar effects on the dynamic characteristics of rod-fastening rotor bearing systems, which lead to fluent whirl and fluent whip appear in advance, reducing the stability of the system.

在这项研究中，建立了圆周分布杆的力学模型和表征圆盘之间接触效应的非线性接触刚度矩阵。接触刚度矩阵由七个刚度系数组成，这些系数表征接触界面的横向刚度，剪切刚度，弯曲刚度和扭转刚度。然后分析了预紧载荷，杆直径，接触表面粗糙度，变形阶段和不均匀的预紧载荷对刚度系数的影响。最后，结合基于短轴承理论的经实验验证的非线性油膜力模型，建立了杆紧固转子-轴承系统的动力学模型。通过频谱级联和坎贝尔图，预紧载荷的影响，数值分析了拉杆直径，接触面粗糙度和不均匀的预紧载荷对拉杆转子轴承系统非线性动力学特性的影响。结果表明，增加预紧载荷可以增加接触刚度，并使杆紧固转子轴承系统的动力学特性更接近完整的转子轴承系统。杆直径的增加显着延迟了接触表面的部分分离。光滑的接触表面可提供更高的接触刚度，但不利于保持接触表面的完全接触状态。刚度系数随转子的变形而波动，并且该过程受到不均匀预紧载荷的显着影响。而且，自激振动频率 数值分析了接触表面粗糙度和不均匀预紧载荷对连杆紧固转子-轴承系统非线性动力学特性的影响。结果表明，增加预紧载荷可以增加接触刚度，并使杆紧固转子轴承系统的动力学特性更接近完整的转子轴承系统。杆直径的增加显着延迟了接触表面的部分分离。光滑的接触表面可提供更高的接触刚度，但不利于保持接触表面的完全接触状态。刚度系数随转子的变形而波动，并且该过程受到不均匀预紧载荷的显着影响。而且，自激振动频率 数值分析了接触表面粗糙度和不均匀预紧载荷对连杆紧固转子-轴承系统非线性动力学特性的影响。结果表明，增加预紧载荷可以增加接触刚度，并使杆紧固转子轴承系统的动力学特性更接近完整的转子轴承系统。杆直径的增加显着延迟了接触表面的部分分离。光滑的接触表面可提供更高的接触刚度，但不利于保持接触表面的完全接触状态。刚度系数随转子的变形而波动，并且该过程受到不均匀预紧载荷的显着影响。而且，自激振动频率当由单个故障杆引起的预紧载荷不均匀时，会出现\（f_ {l} \）和组合频率\（f_ {b} = 3f_ {l} \）。杆的数量，杆的直径和接触表面的粗糙度对杆紧固转子轴承系统的动态特性有相似的影响，这会导致流水涡流和流水鞭提前出现，从而降低了系统的稳定性。