Nonlinear Analysis of Actuation Performance of NiTi/Si Composite Film

The NiTi shape memory alloy (SMA) composite film with Si substrate subjected to thermal loads was modeled by the method of mechanics of materials. The governing equation was obtained by combining static equilibrium equations, geometric and physical equations. Both the material nonlinearity of SMA and the geometric nonlinearity of bending deformation of SMA composite film were considered. By simulating the actuation performance of the SMA composite film during a cooling-heating thermal cycle, it is found that the final cooling temperature and the thickness of SMA film have significant effects on the actuation performance of the SMA composite film. Besides, the maximum deflection of the SMA composite film is affected obviously by the geometric nonlinearity of bending deformation when the thickness of SMA film is very large.