<title>Design of flexible rods with embedded SMA actuators</title>

Abstract

The shape change of a stress free cylindrical flexible rod with embedded SMA actuators is modeled in this paper for rods with single or multiple SMA actuators placed parallel to the long axis of the rod for the first heating of the SMA actuators. The deformed shape of the rod is found by solving the nonlinear equations of equilibrium of the rod. For multiple actuators the resultant forces and moments are considered. A design analysis is performed for the active rod with a single SMA actuator. Key design variables are: E<SUB>ROD</SUB>, the thermal bond strength of the rod to the SMA actuator, and the rod dimensions. Key design parameters are: maximum rod/actuator interfacial shear stress, rod strain, rod slenderness ratio, and rod deflection. An analysis is then performed which investigates the influence of the design variables on each of the design parameters. Optimal values are obtained which yield desired design parameter values. Experimental prototypes are fabricated, tested, and the deformed shape is compared to the theoretical prediction.