Standardization of shape memory alloy test methods toward certification of aerospace applications

Abstract

The response of shape memory alloy (SMA) components employed as actuators has enabled a number of adaptable aero-structural solutions. However, there are currently no industry or government-accepted standardized test methods for SMA materials when used as actuators and their transition to commercialization and production has been hindered. This brief fast track communication introduces to the community a recently initiated collaborative and pre-competitive SMA specification and standardization effort that is expected to deliver the first ever regulatory agency-accepted material specification and test standards for SMA as employed as actuators for commercial and military aviation applications. In the first phase of this effort, described herein, the team is working to review past efforts and deliver a set of agreed-upon properties to be included in future material certification specifications as well as the associated experiments needed to obtain them in a consistent manner. Essential for the success of this project is the participation and input from a number of organizations and individuals, including engineers and designers working in materials and processing development, application design, SMA component fabrication, and testing at the material, component, and system level. Going forward, strong consensus among this diverse body of participants and the SMA research community at large is needed to advance standardization concepts for universal adoption by the greater aerospace community and especially regulatory bodies. It is expected that the development and release of public standards will be done in collaboration with an established standards development organization.

A neural differential evolution identification approach to nonlinear systems and modelling of shape memory alloy actuator

“…This feature gives SMA a promising choice for the actuator that produces an impressive alternative to traditional actuators, for example hydraulic, pneumatic, and motor‐based systems. Although, shape memory alloy has been recently used in lots of applications, for example biomedical engineering , aerospace engineering , robotics , and other domains, the hysteresis behaviors make the SMA actuator a challenge in attaining an accurate dynamic model.…”

Uniaxial Pre-strain and Free Recovery (UPFR) as a Flexible Technique for Nitinol Characterization

“…For 300-lm SE wires, the applied heating rate was 1°C/min. (6) Results are plotted in a deformation versus temperature chart, and transformation temperatures can be determined by the tangent method. A graph of the output is shown in Fig.…”

“…In DSC, cutting and stacking an acceptable sample weight can affect the stress state and the thermal impedance of the wire in the test cell, whereas, in BFR, tracking the wire shape recovery can apply external stresses to the wire and thereby affect the transformation temperatures. Moreover, the lack of a standardized procedure for the evaluation of the functional characteristics of SMA components, especially in aerospace applications, was recently highlighted [6]. It is, therefore, the objective of the present work to establish a technique that can be used for measuring the phase transformation temperatures in shape memory alloy products/components, where the DSC or BFR procedure becomes impractical.…”

Smartphone CanSat for Actualization of Real-time Streaming Video Calls Using Remote Screen Touch System with Shape Memory Alloy Actuator

“…The deformed shape of an SMA at a low temperature below the martensite start temperature can be completely recovered by heating the material above the austenite finish temperature. 19) Hence, SMAs are generally used as smart actuators because they produce a high recovery force during the heating process. 20) For example, Chiang et al 21) developed a 2U cube satellite to observe the electromagnetic waves of Mercury.…”