Research On Mechanical Properties & Precise Control Of SMA Actuator

Shape Memory Alloy(SMA),as a new functional material,with sensing and actuating function integrated,has drawn much attention in diffident fields recently.Scholars around the world carried out many researches and got some achievements of actuators and controllers on intelligent structures.For realization of the SMA actuators,shape memory effect has been investigated.However,it is still in exploring that the mechanical properties,constitutive models and applications of SMA,which more researches needed.The mechanical properties and precise control of actuating force of SMA has been researched in this paper.Firstly,constitutive models raised by Tanaka,Liang and Brinson respectively have been contrastive analyzed.After then Brinson's model has been picked and 12 parameters been measured to establish the specific sample's model.Secondly,the limitation of constitutive model has been exposit by experiment.So comes the presence of calculating model based on experiments,which aim at high or dynamic heating rate.Finally,PID controller of recovery stress with calculated feedback data has been designed.The experiment results show that when set in 76 MPa,114MPa,152 MPa,actual recovery stress would stable in the range of ±5% error band.Controller's maximum overshoot is less than 12.7%.