Research On Bimetallic Strip Actuator Based On Shape Memory Alloy

With the continuous development of intelligent actuating technology,some traditional actuators are gradually replaced by new intelligent actuators,and various advantages of intelligent actuators are emerging in the engineering field.But many excellent traditional actuators still occupy the irreplaceable position,the engineering application of intelligent materials is far from being fully developed,the existing intelligent actuators are still limited by many defects,such as the small driving force and output displacement,complex structure and large dimension.Therefore,it is very necessary to research on the innovative design of intelligent actuators.The basic theory of shape memory alloy was introduced at the beginning of this paper.Then,according to the actuating principle of bimetallic strip,a novel intelligent actuator was proposed based on the mechanical properties of SMA which can provie large recoverable strain and large output force.The bimetallic strip actuator which is based on SMA conmbines the structure and mechanism together,which leads to good load bearing capacity and large displacement output ability,both the angular displacement and linear displacement are available.Theoretical modeling has done on three aspects including the mechanical properties,geometric characteristics and stiffness characteristics,which provides theoretical basis for the structural design and performance analysis of this actuator.According to the theoretical model,the paper analyzed the working performance of bimetallic strip actuators based on SMA.By discreting numerical calculation and drawing diagrams,the paper analyzed the relationship between structure parameters of the actuators and its the performance,some guiding conclusions in engineering application was proposed.The simulation analysis of SMA-based bimetallic strip actuator was carried out by using finite element analysis software.Based on theoretical and simulation analysis,a prototype of SMA-based bimetallic strip actuator was developed and tested experimentally.This paper has carried on the experiment on testing the performance of the new intelligent actuator prototype,the test index contains the output torque,output angle as well as the system stiffness,the experimental test results was contrast with theoretical and simulation results,in the range of allowable error the results are basically consistent,thus proving the validity of the theoretical analysis and has excellent performance of the actuator.At the same time,this paper analyzes the causes of the error of experiment and theory results in detail,and proposes methods to reduce the errors.