The stress created by the austenite transformation of mechanically constrained NiTi shape memory alloys (SMAs) significantly exceeds that required to deform (detwin) its low temperature martensitic phase. The one-way shape memory effect can therefore be used to create antagonistic, fully reversible flexural shape morphing structures by assembling opposing pairs of linear contractile SMA actuators. These structures possess two distinct inactive configurations, neither of which requires continuous power for shape retention making them potentially suitable for long-term applications. Here, the shape changes of a representative antagonistic flexural unit cell have been experimentally evaluated, and the effect of the pre-strain of near equiatomic NiTi alloys on the actuation strain has been analyzed and discussed. The predicted deformations are then successfully compared to the response of prototype actuators.
Baz, A., Chen, T. and Ro, J.2000. ``Shape Control of NITINOL-reinforced Composite Beams ,'' Composites: Part B, 31:631-642.
2.
Beauchamp, C.H., Nadolink, R.H., Dickinson, S.C. and Dean, L.M.1992. ``Shape Memory Alloy Adjustable Camber (SMAAC) Control Surfaces,'' In: Proceedings of the 1st European Conference on Smart Structures and Materials, pp. 189-192.
3.
Bergamasco, M., Dario, P. and Salsedo, F.1990. ``Shape Memory Alloy Microactuators,''Sensors and Actuators, A21-A23:253-257.
4.
Crawly, E.1994. ``Intelligent Structures for Aerospace: A Technology Overview and Assessment,'' AIAA Journal, 32(8):1689-1699.
5.
Duerig, T.W., Melton, K.N., Stöckel, D. and Wayman, 1990 . Engineering Aspects of Shape Memory Alloys, Butterworth-Heinemann Ltd, UK.
6.
Elzey, D.M., Sofla, A.Y.N. and Wadley, H.N.G.2002. ``Shape Memory-based Structural Actuator Panel,'' In: Proceedings of the SPIE - The International Society for Optical Engineering, Vol. 4698, pp. 192-200.
7.
Elzey, D.M., Sofla, A.Y.N. and Wadley, H.N.G.2003. ``A Bio-inspired, High Authority Actuator for Shape Morphing Structures,'' In: Lagoudas, D. (ed.), Proceedings of SPIE: Smart Structures and Materials: Active Materials Behavior and Mechanics, Vol. 5053, pp. 92-100.
8.
Elzey, D.M., Sofla, A.Y.N. and Wadley, H.N.G.2005. ``A Shape Memory-based Multifunctional Structural Actuator Panel,'' International Journal of Solids and Structures , 42:1943-1955.
9.
Giurgiutu, V.2000. ``Review of Smart-materials Actuation Solutions for Aeroelastic and Vibration Control,'' Journal of Intelligent Material Systems and Structures, 11(7):525-544.
10.
Grag, D.P., Zikry, M.A. and Anderson, G.L.2001. ``Current and Potential Future Research Activities in Adaptive Structures: An ARO Prospective,'' Smart Materials and Structures, 10(4):610-623.
11.
Kudva, J.N., Lockyer, A.J. and Appa, K.1996. ``Adaptive Aircraft Wing,''AGARD Lecture Series 205, Smart Structures and Materials: Implications for Military Aircraft of New Generation, Advisory Group for Aerospace Research and Development, Canada.
12.
Lach, C.L., Turner, T.L., Taminger, K.M. and Shenoy, R.N.2002. ``Effects of Thermomechanical History on Tensile Behavior of Nitinol Ribbon,'' In: Proceeding of SPIE, Vol. 4699, pp. 323-334, San Diego, CA .
13.
Lu, T.J., Hutchinson, J.W. and Evans, A.G.2001. ``Optimal Design of a Flexural Actuator,'' Journal of Mech. Phys. Solids, 49(9): 2071-2093.
14.
Miyazaki, S. and Otsuka, K.1986. ``Deformation and Transition Behavior Associated with the R-phase in Ti-Ni Alloys,'' Metallurgical Transactions , 17A:53-63.
15.
Nam, T.H., Kim, J.H., Choi, M.S., Kim, Y.W., Im, H.J., Ahn, J.S. and Mitani, T.2002. ``R-phase Transformation in Equiatomic TiNi Alloy Ribbons Fabricated by Rapid Solidification,'' Journal of Materials Science Letters, 21:685-688.
16.
Otsuka, K.1971. ``Origin of Memory Effect in Cu-Al-Ni Alloy, '' Japanese Journal of Applied Physics, 10(5):571-579.
17.
Otsuka, K. and Wayman, C.M.1998. Shape Memory Materials, Cambridge University Press, New York.
18.
Pelrine, R., Eckerle, J. and Chiba, S.1992. ``Review of Artificial Muscle Approaches,'' In: Proceeding of Third International Symposium on Micro Machine and Human Science, Nagoya, Japan.
19.
Pfaeffle, H.J., Lagoudas, D.C., Tadjbakhsh, I.G. and Craig, K.C.1993. ``Design of Flexible Rods with Embedded SMA Actuators,'' In: Proceedings of SPIE, Vol. 1917, pp. 762-773.
20.
Saburi, T. and Nenno, S.1974. ``Reversible Shape Memory in Cu-Zn-Ga, '' Scripta Metallurgica, 8:1363-1368.
21.
Saburi, T. and Nenno, S.1982. ``Shape Memory Effect and Relate Phenomena,'' In: Proceedings of International Conference On Solid-Solid Phase Transformations, pp. 1455-1479, AIME, NY.
22.
Schroeder, T.A. and Wayman, C.M.1977. ``The Two-way Shape Memory Effect and Other ``training'' Phenomena in Cu-Zn Single Crystals,'' Scripta Metallurgica , 11(3):225-230.
23.
Sittner, P., Lugovyy, D., Neov, D., Landa, M., Lukas, P. and Novak, V.2004. ``On the R-phase Transformation Related Phenomena in NiTi Polycrystals Subjected to Thermomechanical Loads,''J. Phys. IV France, 115:269-278.
24.
Sofla, A.Y.N., Elzey, D.M. and Wadley, H.N.G.2004. ``An Antagonistic Flexural Unit Cell for Design of Shape Morphing Structures,'' In: Proceedings of the ASME Aerospace Division: Adaptive Materials and Systems, Aerospace Materials and Structures, pp. 261-269, Anaheim, CA.
25.
Strelec, J.K. and Lagoudas, D.C.2002. ``Fabrication and Testing of a Shape Memory Alloy Actuated Reconfigurable Wing,'' In: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 4701, pp. 267-280.
26.
Takagi, T.1999. ``Present State and Future of Intelligent Materials and Systems in Japan,'' Journal of Intelligent Material Systems and Structures, 10(7):575-581.
27.
Tobushi, H., Hayashi, S. and Kojima, S.1992. ``Mechanical Properties of Shape Memory Polymer of Polyurethane Series,''JSME International Journal, Series I (Solid Mechanics, Strength of Materials), 35(3):296-302.
Van der Wijst, M.W.M., Zuidervaart, J., Peijs, T. and Schreurs, P.J.G.1997. ``Active Shape Control of Shape Memory Alloy Composite Structures,'' In: Proceeding of ICCM-11, pp. 561-570, Gold Coast, Australia.
30.
Wada, B.K.1990. ``Adaptive Structures - An Overview, '' Journal of Spacecraft and Rockets, 27(3):330-337.
31.
Wang, Z.G., Zu, X.T. and Fu, Y.Q.2005. ``Study of Incomplete Transformations of Near Equiatomic TiNi Shape Memory Alloys by DSC Method,''Materials Science & Engineering A (Structural Materials: Properties, Microstructure and Processing), 390(1-2):400-403.
32.
White, S.R. and Berman, J.B.1998. ``Thermomechanical Response of SMA Composite Beams with Embedded Nitinol Wires in an Epoxy Matrix,'' Journal of Intelligent Material Systems and Structures, 9(5):391-400.
