Research On Optimal Design In Magnetic Field And Characteristics Of Giant Magnetostrictive Actuator

Giant magnetostrictive material is a very promising functional material,which is widely used.In this thesis a giant magnetostrictive actuator is designed targeting at optimal magnetic field.Simulation is carried out to study its magnetic field and output characteristics.According to its output characteristic test rig is designed,and experiments of output characteristic are carried out under different conditions.There are three procedures in the design of magnetic system:driving magnetic field,bias magnetic field and magnetic circuit.In the design of the bias magnetic field,this thesis refers to several arrangements of permanent magnet,puts forward the arrangement of multi-segmented permanent magnets,through changing the arrangement to improve the efficiency of the bias magnetic field.In the design of driving magnetic field,the coil is designed using the perspective of power optimization.In order to obtain closed magnetic circuit and make the output displacement maximum,magnetic circuit is optimized designed through the theoretical calculation.Eventually the structure size of the actuator is confirmed.The software ANSOFT and MATLAB are used to simulate the static and dynamic characteristics of magnetic field and output displacement,respectively.Simulation result not only validates the design of the magnetic field is rational,but also reveal the good output characteristic of the actuator.A test rig based on the theoretical studies is built,which realizes the continuity of changing load quality,also permits simultaneous measurement of output force and output displacement.Experiments are carried out to study the static and dynamic displacement output characteristic under different situations.Static displacement actuator output characteristics and force output characteristic show that the phenomenon of actuator hysteresis is not obvious,and output displacement and output force have good linearity.Dynamic output characteristics show that the response of the actuator is fast and the frequency of output force and output displacement are the same with excitation.Experimental and simulation results show that the designed giant magnetostrictive actuator has large output force and output displacement.Its good performance could be applied in active vibration control.