Study On The Magneto-induced Characteristics Of Magnetorheological Elastomer And Actuator Design For Rotor Vibration Suppression

Rotating machines with the rotor system as the main body of operation,such as compressors,centrifugal pumps,steam turbines,fans,and aero engines,often generate different degrees of rotor vibration for various reasons during operation.Excessive rotor vibration will affect the normal operation of the equipment and may even lead to serious safety accidents.Therefore,it is necessary to actively suppress the vibration of the rotor system.Magneto-rheological elastomer(MRE)is a new type of magnetic control smart material prepared by curing a polymer matrix filled with micron-sized magnetic particles.The characteristics of rapid,continuous and reversible magnetic control variable stiffness shows great potential in the field of vibration control.According to the vibration characteristics of the rotor system,the MRE-based actuator can adjust the inherent parameters of the rotor system and suppress the vibration effectively.In view of the potential application of MRE in the field of rotor vibration control,materials preparation,performance characterization,mechanism research,performance improvement,and actuator design are studied in this paper.The main work of this paper is as follows:(1)The fabrication method of addition type liquid silicone rubber-based MRE was proposed,and the MRE sample preparation and magneto-induced properties test were completed.Through the establishment of the preparation platform and the exploration of the preparation process,the preparation process of addition type liquid silicone rubber-based MRE was mastered;the dynamic shear viscoelastic properties of the samples were tested,and the influence of particle arrangement structure and particle mass fc-action,particle size,shear strain and shear frequency on its magneto-induced properties were mastered,which laid a theoretical foundation for subsequent actuator design.(2)A method is proposed to improve the magneto-induced modulus and mechanical properties of MRE simultaneously.Aiming at the contradiction between the effect of variable stiffness and good mechanical properties of MRE,from the perspective of magnetic dipole theory,a microscopic model of magneto-induced modulus of MRE is established when there is an orientation angle between the internal particle chain and the external magnetic field.The model reveals the variation of the magneto-induced modulus with the orientation angle of the particle chain.Double optimization of variable stiffness range and mechanical properties can be achieved under certain angles of orientation.The accuracy of the model and the feasibility of the method are verified by numerical simulation and experimental research.Increasing the MRE variable stiffness range by adjusting the grain chain orientation angle at the same magnetic particle content helps to expand the frequency shift range under the applied magnetic field.(3)Based on the excellent magnetic control variable stiffness characteristics of MRE,an actuator is designed which MRE in shear-extrusion compound mode.Aiming at the vibration characteristics of the rotor and the shortcomings of MRE in a single working mode,the designed actuator can withstand large loads while achieving large stiffness changes,its working principle is introduced.The actuator structure design,magnetic circuit analysis,processing and installation were completed,which laid the foundation for subsequent experimental research.