Research On Multilayer Steel Plate Rotor Damper And Related Technologies

As a rotor is the main part in the equipment with a high rotation speed, its working performance determines the lifetime of the whole system directly. Therefore, the vibration control for high rotation speed equipment is an key technology in practical applications. Researchers in Soviet Union developed a kind of dry friction damper, named multi-layer steel plate damper, which performed well enduring high or low temperature and overcoming the disadvantages of squeeze film dampers, such as the complex structure, the strong nonlinearity, and the temperature-influenced properties. The multi-layer steel plate damper could be used as a support in a rotor system with compact structural space working at high or low temperature, or large temperature difference. However, the application of the damper is not practicable presently in high-speed rotor systems in China because of the technology blockage between countries.In the present study, the discussion on the characteristics of dampers with different wave shapes based on its geometric structure was first presented. The curve equation of multi layer steel plates was optimized. The fabrication process of wave curves of damper was presented after selecting appropriate material. Then, the related parameters for shaping the curved steel plate were studied to determine the assembling process of the damper.The load on the damper can be divided into pre-deformation and radial loads. In the research, the damper was modelled into continuous bending beams, on which the stiffness performance under these two kinds of loads was theoretically explored, respectively. In the analysis of pre-deformation, based on the symmetry of load and structure, the force method was used to solve statically indeterminate problems. Then, the deflection of bending beam caused by pre-deformation was analyzed on the basis of elastic contact bending deformation theory to get the stiffness characteristics of the damper. To analyze radial load on the damper, the radial stiffness of the damper was calculated through the force projection with an assumption of a linear relation between the force and the displacement. The theoretical analysis was verified by comparing the experimental and calculated results. The effect of the friction at the contact surface on the dynamic parameters of damper was analyzed considering the interactions between adjacent layers in the damper and interaction between the damper and the inner/outer rings. The friction force at the contact interfaces of damper was calculated based on the modeling method of dry friction system, and its effect on the stiffness of damper was analyzed. In the study, the Mindlin contact model was adopted to analyze the friction in the steel plates of damper and the energy dissipation in the process of deformation by formulatiing energy dissipation in the damper. The contact behavior between layers was simulated with finite element method.Based on the rotor experimental platform, the dynamic model of rotor system supported by the multi-layer steel plate damper was developed based on Hamilton principle. The natural frequency of the rotor system was obtained by deriving the stiffness coefficient of the rotor system. A numerical method was used to solve the equation of motion of rotor system to obtain the critical rotation speed and other essential parameters of the system.A series of experiments related to the damper and the rotor system wre explored. Through the static experiments, the hysteresis loop of the multi-layer steel plate damper with different parameters and work conditions was presented. The stiffness and the energy dissipation coefficient of the damper were verified. The effect of the structural and geometric parameters of the damper on its dynamic performance was presented. The former theoretical analysis was verified by the experimental results. With the help of a test setup, the dynamic behavior of the rotor with a support of multi-layer steel plate damper and a high rotation speed was studied. The response of the rotor system under different working conditions was obtained. These experimental results are helpful for the practical application of multi-layer steel plate damper.This study is a part of the research project named"Research on Multi-Layer Steel Plate Damper with Dry Friction and Viscosity Damping"sponsored by National Natural Science Foundation of China (Grant Number: 50275030).