Design & Research Of Microdisplacement Actuator Based On Giant Magnetostrictive Materials

Rare Earth Giant Magnetostrictive Materials(GMM) is a new kind of smart material developed in recent years, which has several inherent excellent properties, such as large magnetostrictive strain, fast response, high energy density and so on. Because of its excellent property and promising application foreground, scientists all over the world are interested in it.The paper includes six chapters,content of each chapter is stated as follows.In chapter one and chapter two.the giant magnetostrictive material and its main features are introduced briefly. First,the mechanism of magnetostriction,the overpassed and current reseach situations are summarized.Second,the significance and main aspects of this reseach project are addressed. Third,the characteristics of magnetization saturation, ma gnetoelastic coupling, magnetostrictive strain, sensitivity of performance to operation conditions, hysteresis,nonlinear dynamics, AE effect,eddy current influence and double frequency property are addressed.Finally,the characteristics measurement methods and results of GMM are introduced.The measurement results supported design of application apparatus.Chapter three concerns static and dynamic modelling of Giant Magnetostrictive Actuators(GMA).Two static model is presented, and two kind of lump parameter dynamic modelling methods are addressed. Lump parameter dynamic models has obvious distortion when the inductance of solenoid is treated as a constant.Simulation result showes better coherence with experiment result after flux feedback is introduced into the model.An energy-based hysteresis model is presented to describe the nonlinear input-output characteristic of Giant Magnetostrictive Actuators.Chapter four discusses Giant Magnetostrictive Actuator's design,include mechanical structure design, electromagnetic structure design and magnetostrictive rod's temperature control system design.A new design idea is put forward that pumbed-water-cooling system and phase change set is used to control the magnetostrictive rod's temperature together.Giant Magnetostrictive Actuator's drive and control method is described in Chapter five.Before design the control system,GMA's static and dynamic characteristics must be studied by experiment.The static test includes static displacement and force output,while dynamic test covers the repeatability, linearity,hysteresis property and response speed of the dynamic output of GMA.The temperature increase of magnetostrictive rod is also tested.Chapter six: summarizes the work of this dissertation and puts forward the future research work.