<title>SMA actuator for tab-assisted control surface application</title>

Shape Memory Actuators for Tab-Assisted Control Surfaces

“…Very limited experimental work using SMA's in a flowing water environment exists. The two most noteworthy efforts are, of course, the TAC work at NSWCCD [6] and the efforts of Lagoudas at Texas A&M [7], also funded by the Navy (under the STTR program, N0014-98-C-0061, monitored by Dr. Teresa McMullen). Our analysis is motivated by these efforts, plus the monthly reports submitted by NSWCCD and the open literature on SMA actuation.…”

“…All of the relevant values for design (torque, bandwidth, power and time constant) in open-loop servo control depend on the solution of equations (4) and (6). Because H appears in the numerator of each of these equations, an order of magnitude change in H will overshadow any design choice.…”

“…This time constant cannot be determined without the specific load profiles to be experienced by the tab. However, the appropriate and key parameters can be identified from equations (1) through (6). Most of these parameters are not available from analytical or published numerical sources.…”

“…Using an antagonistic actuation of a compliant control surface, as suggested in [6], may be the best mechanism from the point of view of the heat transfer problem. This would at least change the heat transfer coefficient (H) from 3500 to 890, thus reducing the amount of power required by a factor of four, or alternately, increasing the actuation efficiency by a factor of four.…”