温度对磁流变弹性体力学性能的影响分析

Influence of Temperature on the Mechanical Properties of Magnetorheological Elastomers

温度影响磁流变弹性体硅橡胶或天然橡胶基体的剪切模量与损耗因数,进而影响磁流变弹性体的减振性能。研究温度对磁流变弹性体力学性能的影响,首先通过ANSYS Workbench仿真分析磁流变弹性体减振器工作时温度随工作时间变化过程,发现磁流变弹性体减振器中励磁线圈随着时间增加,温度逐渐上升,导致磁流变弹性体升温幅度测试磁流变弹性体试样在不同剪切应变与激励频率条件下的力学性能随温度变化过程。结果表明,温度对磁流变弹性体的剪切模量与损耗因数影响较大,在50 Hz、2.5%剪切应变的条件下,试样的剪切模量由25°C时的0.42 MPa降低到65°C时的0.36 MPa,损耗因数由0.307降低到0.204,降幅为33.55%,在不同温度下,磁致性能随温度变化相对较小。基于MATLAB动力学仿真,表明无外加磁场条件下磁流变弹性体减振器系统传递率由25°C时的5.065升高到65°C时的6.705,增幅为32.38%。

Temperature can affect the shear modulus and loss factor of the silicone rubber or natural rubber matrix of magnetorheological(MR)elastomers,and moreover affect the vibration damping properties of the MR elastomers.In this paper,the influence of temperature on the mechanical properties of the MR elastomers is studied.Firstly,ANSYS Workbench is used to simulate the change of temperature vs.the working time during the operation of MR elastomer damper.It is found that when the temperature of the magnetizing coil in the MR elastomer damper rises gradually,the temperature rising magnitude of the MR elastomer increases greatly.The rheological test of the MR elastomer sample is carried out to test the change of the mechanical properties of the sample vs.the temperature under different shear strain and excitation frequency.The results show that the temperature has a great influence on the shear modulus and loss factor of the MR elastomer.Under the condition of 50 Hz and 2.5%shear strain,the shear modulus of the sample is reduced from 0.42 MPa at 25°C to 0.36 MPa at 65°C,the loss factor is reduced from 0.307 at 25°C to 0.204 at 65°C,and the decrease magnitude is 33.55%.At different temperatures,the magnetic properties vary slightly with temperature.Using the dynamic model established in MATLAB,it is obtained that the transfer rate of the MR elastomer damper system without external magnetic field is increased from 5.065 at 25°C to 6.705 at 65°C,the increasing magnitude is 32.38%.