Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

Experimental and computational thermomechanical study of a shape-memory alloy micro-actuator: aspects of antagonist-type behavior

R. Velázqueza,*, M. Hafezb, J. Szewczyka, E. Pissalouxa
aLaboratoire de Robotique de Paris and CNRS FRE 2507, 18 Route du Panorama, BP 61, 92265 Fontenay aux Roses, France bCEA/LIST, 18 Route du Panorama, BP 61, 92265 Fontenay aux Roses, France

  Full Text
A combined computational/experimental study of a shape-memory alloy (SMA) linear micro-actuator based on the working principle of antagonist configuration is presented. An electrically driven NiTi helical spring is used as the active element in such an actuator. The thermomechanical properties of the fabricated SMA spring were evaluated using a constitutive model and investigated experimentally through two types of tests: isothermal loading/unloading and fatigue due to plastic strain development. Both experimental and computational results are in good agreement and are used to characterize the actuator's SMA antagonist-type behavior.

Keywords:  SMA; Helical spring; Antagonist actuator; Thermomechanical property; Fatigue

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