Effect Of Rare Earth Giant Magnetostrictive Actuator On Output Characteristics

In recent years,with the advancement of social technology,the research and application of smart materials in various fields have been paid more and more attention and development.Rare earth giant magnetostrictive materials(GMM)as a new type of intelligent materials,its magnetostriction coefficient is much greater than other ferromagnetic materials,widely used in various fields.The Giant Magnetostrictive Actuator(GMA)is a drive mechanism with GMM rods as its core.It uses the magnetostrictive effect of GMM materials to output displacements.It has large output force,fast response speed,high energy density and frequency characteristics.Many advantages,such as good,have been rapidly applied in the fields of microelectronics technology,modern medical machinery and aerospace,but the problem of insufficient output characteristics of GMA has always plagued the development of the industry.In this paper,from the perspective of the bias magnetic field,the effect of the structural parameters of the permanent magnet applying the bias magnetic field on the performance of the driver is studied.Secondly,the structure of the permanent magnet applying the bias magnetic field is improved.Finally,a two-stage displacement amplification mechanism is designed.The main content and the conclusion is as follows:(1)The influence of the structural parameters of the permanent magnet applied to the bias magnetic field on the performance of the driver is studied.The GMA simulation model was established using finite element software,the simulation environment was set up,and the influence of the two parameters of the thickness of the permanent magnet and the distance between the permanent magnet and the coil on the performance of the driver was compared and analyzed using the magnetic field distribution of the GMM rod and the output displacement of the driver as the evaluation criteria.The results show that as the thickness of the permanent magnet increases,the magnetic field distribution law is improved,the uniformity of the magnetic field is improved,and the output displacement is increased;as the distance between the permanent magnet and the coil increases,the magnetic induction intensity in the GMM rod decreases and the output displacement It is reduced,but the uniformity of the magnetic field is improved;the thickness of the permanent magnet is 6mm,and the distance between the permanent magnet and the coil is 1.5mm.(2)The influence of the structure distribution of the permanent magnet applied with a bias magnetic field on the performance of the driver was studied.Analyze the influence of the change of the layer number of the ring-shaped permanent magnet on the magnetic field distribution and output displacement of the driver,improve the ring-shaped permanent magnet according to the distribution principle of more middle and less ends,and analyze its impact on the magnetic field and output displacement of the driver.The corresponding driver model is established by finite element software,and the time-domain diagram of the magnetic field distribution and output displacement in the driver is analyzed by steady state and transient state.The results show that as the number of annular permanent magnet layers increases,the magnetic field uniformity and output displacement of the GMM rod both increase first and then tend to be gentle,and the impact on the performance of the driver is gradually weakened;the annular permanent magnet bias is improved The magnetic structure,the uniformity of the magnetic field in the GMM rod and the output displacement have been improved,that is,the improved model is conducive to improving the performance of the magnetostrictive drive.(3)In view of the insufficient output characteristics of the magnetostrictive driver,using the characteristics of flexible hinges,the principle of lever and the principle of static balance,a two-stage displacement amplification mechanism was designed to amplify the output displacement of the driver.Based on the offset of the rotation center of the flexible hinge,the magnification formula of the amplifying mechanism is derived,and the size parameters of the structure are given.The design is modeled and simulated to verify the rationality of the structure.The results show that the magnification of the magnifying mechanism is affected by the width of the flexible hinge and the size of the arc cutting part.With the increase of the ratio S,the magnification shows a trend of increasing first and then gradually smoothing.The size of the arc-cut portion of the flexible hinge has a greater influence on the magnification;the magnification gradually decreases with the increase of the width b and tends with a stable trend,the width b of the flexible hinge has little effect on the magnification.Through the research in this paper,the influence of the permanent magnet structure applied to the bias magnetic field on the performance of the rare earth giant magnetostrictive drive is obtained,and an amplification mechanism is designed,which can flexibly use the permanent magnet structure in practical applications and has a certain guiding role.