Lightweight structures capable of changing their shape on demand are of interest for a number of applications, including aerospace, power generation, and undersea vehicles. This paper describes a bio-inspired cellular metal vertebrate structure which relies on shape memory alloy (SMA) faces to achieve fully reversing shape change. The resulting vertebrate actuators can be combined with flexible face sheets to create a load-bearing, shape morphing panel. Performance of the vertebrate actuator in terms of maximum curvature and moment is analyzed and discussed. A recently constructed, prototype shape morphing airfoil is used to illustrate the concept.
A multifunctional panel concept is presented in which a lightweight, structural sandwich panel is able to undergo a reversible change in shape upon application of a localized thermal stimulus. The shape change is effected by metallic shape memory face sheet elements, which employ a 'one-way' SM effect only. Unlike other designs, no external or bias forces are required to completed the full cycle of shape change. This is accomplished by a core design which, when one of the two face sheets is activated and thus undergoes a length change, forces the opposite face sheet to martensitically deform in tension. By alternately heating one face sheet and then the other, to transform the martensitic structure to austenite, the sandwich beam or panel is able to perform fully reversible cyclic shape changes. Heating can be accomplished electrically or by other means. The performance of the sandwich panel, in terms of required thermal power, actuation frequency, peak load bearing capacity, stiffness, and weight, can be optimized by proper selection of face sheet material and this thickness, the overall core thickness, core member thickness and length, and the design of the joint connecting cor membranes and face sheet.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.