Shape Memory Alloy Actuator Design: CASMART Collaborative Best Practices

Abstract

Upon examination of shape memory alloy (SMA) actuation designs, there are many considerations and methodologies that are common to them all. A goal of CASMART's design working group is to compile the collective experiences of CASMART's member organizations into a single medium that engineers can then use to make the best decisions regarding SMA system design. In this paper, a review of recent work toward this goal is presented, spanning a wide range of design aspects including evaluation, properties, testing, modeling, alloy selection, fabrication, actuator processing, design optimization, controls, and system integration. We have documented each aspect, based on our collective experiences, so that the design engineer may access the tools and information needed to successfully design and develop SMA systems. Through comparison of several case studies, it is shown that there is not an obvious single, linear route a designer can adopt to navigate the path of concept to product. SMA engineering aspects will have different priorities and emphasis for different applications. INTRODUCTIONShape memory alloys (SMAs) have been a topic of significant research interest for over forty years. Microstructural complexities and their resulting thermomechanical properties have presented challenges in understanding how to integrate these materials into structural applications.Consequently, design of structural and mechanical systems involving SMA materials has been sparse and ad hoc. However, upon examination of a variety of system designs, there are many considerations and parameters that are common to them all. The Consortium for the Advancement of Shape Memory Alloy Research and Technology (CASMART) was established to foster sharing of technical knowledge about SMAs, to achieve new understanding of the materials, and to facilitate progress in applying that knowledge. The Design Working Group of CASMART strives to serve as a single location to capture the collective best practices, critical information and perspective necessary for designing systems involving SMA materials and actuators.The objective of this paper is to compile the experiences of the authors into a resource that can aid other engineers in SMA

Applicability of Shape Memory Alloys in Aircraft Interiors

“…Phase transformation temperature is an SMA characteristic greatly depended on alloy components [5,39,46]. Therefore the material choice is rated with "5".…”

“…The compactness of an SMA actuator is largely determined by the number, size and interaction of the necessary components [24,46]. Accordingly, the rating of the attributes in this row is mainly determined by these factors.…”

Effect of Material Change on Stirnol Engine: A Combination of NiTiNOL (Shape Memory Alloy) and Gamma Stirling Engine

“…Owing to this unique characteristic, these materials are being used in many scientific types of research and a variety of industrial applications such as biomedical devices, automation, and robotics industries [3]. SMA elements can be of a variety of forms (strips, rods, sheets, wires, springs, tubes) in various sizes [4]. In the research that follows, spring-shaped NiTiNOL is used.…”

Engineering design tools for shape memory alloy actuators: CASMART collaborative best practices and case studies

“…Moreover, these tools need to be adequately formulated to account for material properties, boundary conditions, stroke and power requirements, and other SMA actuation attributes to inform the choice for an optimum design solution. Depending on the design method and where the user is in the design process, the tools could be first-order calculations, engineering models, or even more sophisticated constitutive approaches (An et al, 2012;Benafan et al,2011Benafan et al, , 2014Czarnocki et al, 2013;Lagoudas, 2008;Saleeb et al, 2011;Stebner and Brinson, 2013;Turner, 2000).…”