Research On Axial-radial Two-dimensional Stack Magnetostrictive Rods-based Displacement Amplification Actuator

Active Control Technology of Aero-Engine is one of the most promising key technologies for the development of high-performance aero engines in the future.High-frequency response actuators are the key common technology of Active Control Technology of Aero-Engine.It is possible for smart materials to achieve this key technology due to their high-frequency characteristics.However,they have the disadvantage of small output displacement.Therefore,many scholars at home and abroad have proposed many displacement amplification mechanisms.These mechanisms have significant displacement amplification effects but have many disadvantages such as poor high-frequency characteristics and they need to rely on external mechanical structures.Therefore,this paper proposes an axial-radial two-dimensional stack structure for the micro-displacement amplification of magnetostrictive materials and carries out relevant theoretical and experimental research on this structure.Firstly,two kinds of magnetostrictive materials are introduced,including Galfenol material and Terfenol-D material.According to the relevant characteristics of the materials,the two-dimensional stack structure used for the micro-displacement amplification of magnetostrictive materials is proposed in this paper.The working principle and structural design of the two-dimensional stack structure are introduced in detail and it also describes the design details of the actuator that need to pay attention to during the design process.Secondly,according to the structure of Galfenol rods-based actuator and Terfenol-D rods-based actuator,a two-dimensional symmetrical finite element simulation model is established in the finite element simulation software COMSOL Multiphysics,and the magnetic field distribution simulation analysis inside the actuator is carried out,mainly considering the material,the axial and radial dimensions of the sleeve and the corresponding design suggestions are put forward.Thirdly,the mathematical simulation model of the actuator is established by using MATLAB/Simulink module to describe the output characteristics of the actuator.In order to improve the accuracy of the mathematical model,the identification module in the Simulink are used to identify some parameters in the mathematical model.In this paper,The mathematical model is used to simulate and analyze many variables in the electrical-mechanical energy conversion process of actuator and study the theory of N-level stack of two-dimensional stack magnetostrictive rods-based actuator,and the five-level stack Galfenol rods-based actuator is taken as an example for simulation analysis.The results show that the amplification ratio of the five-level stack Galfenol rods-based actuator can be more than 4 at 1Hz.Then,the experimental research on Galfenol rods-based actuator and Terfenol-D rods-based actuator is carried out.The research results show that the proposed two-dimensional stack structure has an obvious effect on the displacement amplification of magnetostrictive materials,and its amplification ratio mainly depends on the number of magnetostrictive rods in the two-dimensional stack structure.In addition,it can be seen that the two-dimensional stack structure can maintain the high-frequency response characteristics of magnetostrictive materials well.The bandwidth of Galfenol actuator can reach 700 Hz,and the bandwidth of Terfenol-D actuator can exceed 500 Hz.Through the comparison of simulation and experiment,it can be found that the mathematical model established in this paper has good accuracy.Finally,the application of the actuator is studied,and the two-dimensional stack magnetostrictive actuator(Terfenol-D material)is used for driving the electro-hydrostatic actuator.The experimental results show that the two-dimensional stack structure plays an important role in improving the performance of the actuator.The peak frequency of the actuator is about 180 Hz to 200 Hz,the maximum output flow at no load is 0.71L/min,and the maximum output flow at 8kg is 0.43 L/min.The main innovation of this paper: Aiming at the shortcoming of small output displacement of stacked magnetostrictive materials,an axial-radial two-dimensional stack displacement amplification structure was proposed.Compared with other displacement amplification mechanisms,it has the significant effect of displacement amplification and can maintain the high-frequency characteristics of magnetostrictive materials at the same time.It has the advantages of good high-frequency characteristics,small space volume and no need for external mechanical structures.