Study On The Magneto-induced Mechanical Characteristics Of Magnetorheological Elastomer And MRE Actuator Properties

Rotating machinery plays an important role as power output and transmission device in the fields of aerospace,shipbuilding,automobile,electricity and petrochemical.The vibration problem is becoming more and more serious with the increasingly complex structure of modern rotating machinery and the increasing speed of rotation.How to effectively suppress the vibration of rotating machinery becomes a research hotspot and a difficulty.Magnetorheological elastomer(MRE)is a mixture of polymer matrix and micron-sized magnetic particles.The mechanical properties of MRE,such as elastic modulus and damping,can be changed rapidly and reversibly under the application of external magnetic field.MRE has excellent potential in the field of vibration suppression of rotating machinery.In view of the potential application of MRE in vibration suppression of rotating machinery,the materials fabrication,performance testing and macro modeling of MRE,and MRE actuator performance has been studied in this work.The main contents of this thesis are as follows:(1)The preparation of MRE with particle chain orientation angle has been performed.The fabrication platform of silicone rubber-based MRE was built and the preparation process was improved.The preparation efficiency and the accuracy of the orientation angle are effectively improved.MRE specimens with different initial particle chain orientation angles have been designed and fabricated.(2)The dynamic mechanical properties tests of MRE samples with the different initial particle chain orientation angles under shear working mode have been carried out.The dynamic viscoelastic properties of MRE with different initial inclination angles are analyzed under the test conditions of different strain amplitude,frequency and magnetic flux density.The MR effect and Payne effect of MRE have been discussed.The test results show that the MR effect of MRE can be improved by changing the orientation angle of particle chains inside MRE.(3)The macroscopic viscoelastic model of MRE based on fractional derivatives is proposed.A macroscopic viscoelastic modeling method for MRE based on fractional derivative model is presented to describe the dynamic viscoelastic properties of MRE with different initial particle chain orientation angles.The model parameters are identified using the nonlinear least square method and the nonlinear regression algorithm,respectively.The predicted values of the model are in good agreement with the experimental results,indicating that the model can well describe the dynamic viscoelastic properties of MRE.(4)The MRE with particle chain orientation angle-based actuator performance testing has been completed.The MRE with particle chain orientation angle was used as the sensitive element of the actuator,and the testing platform of the MRE actuator has been built.The speed-up experiment of the rotor-MRE actuator system under constant voltage has been applied to measure frequency shifting properties of the rotor system.The effect of MRE with different matrix materials,carbonyl iron powder concentrations and initial particle chain orientation angles on the frequency shifting properties of rotorMRE actuator system was analyzed.This study provides support for design and optimization of MRE actuator.