用分形接触理论研究拉杆转子轴承系统动力学模型
Dynamic Model Research of Rod Fastening Composite Special Rotor-bearing System with Fractal Contacting Theory

根据分形接触理论，建立了拉杆转子轮盘结合面弹性接触弯曲耦合模型和扭转耦合模型。在此基础上，采用集总参数法，建立了拉杆转子-轴承系统的动力学模型。通过锤击试验，测量了拉杆转子自由状态下的固有频率，验证了该模型的有效性。借助于数值仿真方法，研究了系统横向振动固有频率和扭转振动固有频率随结合面法向载荷的变化规律。研究发现：分形接触理论可以有效地解决拉杆转子轮盘接触表面间的弹性接触问题；结合面法向载荷增大时，系统固有频率同步增大；拉杆转子的固有频率小于相同结构尺寸的连续体转子的固有频率；法向载荷对高阶固有频率影响较大；对滑动轴承支承的拉杆转子轴承系统来说，拉杆转子预紧力对低阶横向振动和扭转振动固有频率影响相对较小。
By means of fractal contacting theory, in the case of consideration of elastic contacting characteristics between two plates of the rod fastening composite special rotor, bending coupling model and twist coupling model were established. Furthermore, the dynamic model of the rod fastening composite special rotor-bearing system was established by Lumped Parameter Method. By impact test, the natural frequencies of the rod fastening composite special rotor in free state were measured, which are used to verify the model. By means of numerical simulation, the natural frequencies of bending and twisting vibration of the system were researched. It was found that fractal contacting theory was appropriate to solve the elastic contacting problem. The natural frequencies were varied with normal load between contacting surfaces. The natural frequencies of the rod fastening composite special rotor are less than the solid rotor with same size and structure. Higher order natural frequencies are seriously influenced by normal loads. Lower natural frequencies of the rod fastening composite special rotor supported by the hydraulic bearing are hardly influenced by normal loads relatively