Application Of Particle Damper Nonlinear Energy Sink In Vibration Suppression Of Rotor System

The rotor system will vibrate when it runs.Nowadays high speed and heavy load become the development goal of the advanced manufacturing industry.The rotor system is bound to pass through its critical speed and causes resonance during the starting and stopping process.It is important to suppress the rotor system vibration,since the severe vibration prevents rotor system working normally and even causes accidents.Nonlinear energy sink(NES)has a simple structure and wide vibration suppression frequency band,which combines the advantages of passive and active vibration absorbers.It becomes a new method of rotor vibration attenuation.Most NES studies focus on the design of nonlinear stiffness currently,and lack the concern of NES damping parameters.In fact,the damping of NES plays a significant role in the targeted energy transfer(TET)mechanism and improving vibration suppression performance of NES.Considering that particle damping(PD)technology is easy to control,particle damping is introduced into the damping design of nonlinear energy sink.In this thesis,a novel particle damper nonlinear energy sink(PDNES)is proposed to improve the vibration suppression ability of NES.Then the vibration suppression performance of PDNES is simulated numerically and verified experimentally.The 4 main contents of this thesis are as follows.(1)A mechanical structure of particle damper nonlinear energy sink for rotor system is designed.Piecewise linear stiffness is used to fit cubic stiffness as PDNES nonlinear stiffness.The dynamic model of particle damping is established by two-phase flow theory of gas-solid.The dynamic model of rotor system is established by finite element method.(2)The vibration suppression ability of PDNES is simulated numerically.The displacement attenuation speed of rotor systems without any vibration absorber,with linear dynamic vibration absorber(LDVA),with ordinary NES without particle damping(hereinafter referred to as ordinary NES)and with PDNES are compared under different pulse excitations.The steady state amplitudes of the rotor system under the above 4 conditions are compared under different periodic unbalanced forces.(3)PDNES is optimized.Some parameters of PDNES and particle damper,such as PDNES stiffness,mass parameters,installed location on the shaft,cavity dimensions,particle filling rate,particle materials and diameters are used to analyze the influence on the vibration suppression effect of PDNES.The PDNES parameters are optimized according to the above rules.Then the vibration suppression performance of optimized PDNES is analyzed.(4)PDNES is verified by experiment.Firstly,the experimental platform of single disk rotor system-PDNES is set up.Then the transient vibration attenuation speed of PDNES and ordinary NES under impact excitations are verified.At last,the steady vibration suppression ability of PDNES and ordinary NES under unbalanced excitations are verified.