Bi-stable Nonlinear Energy Sink Applied To Vibration Suppression Of Rotor System

Vibration is an inevitable phenomenon in the rotation of the rotor system.Severe vibration will endanger the healthy operation of the rotating machinery and even cause serious damage.Therefore,vibration suppression is one of the technical hotspots related to the safe operation of the rotor system.Vibration absorber is an important way of vibration suppression,which can be divided into passive type and semi-active(or active)type.The passive vibration absorber has a simple structure,but the effective absorption frequency band is narrow;The active vibration absorber has a wide suppress frequency band,but the structure is complex and the reliability is low.The proposed nonlinear energy sink(NES)solves the obvious defects of the two type conventional vibration absorbers,but the energy threshold is still narrow,which limits its wide range of engineering applications.Based on the above background and problems,this paper addes the buckled beam with negative stiffness to NES,designs the structure of BNES,and applies it to the rotor system for vibration suppression analysis.The main research contents of this paper are as follows:(1)The specific structure of BNES is designed.The working mode and working state of BNES is explained.The mechanical relationship between the end load and displacement of the buckled beams is analyzed.The dynamic model of BNES system and rotor-BNES system are established.(2)The rotor-BNES system dynamics equation is established.The vibration amplitude decay rate of rotor system with and without BNES are compared.The vibration energy trend is analyzed.The suppression band of BNES is studied.The vibration suppression of the rotor by the BNES is explored.(3)The various parameter influences of BNES on the vibration suppression effect of the rotor system is analyzed.The parameters with large influence are optimized.The optimal vibration suppression parameters of BNES are obtained.(4)The system test rig with isotropic rotor and the BNES is built.The correctness of the simulation analysis is verified.The influence of BNES parameters on the experimental vibration suppression effect is explored.