Bend it, shape it, remember it Shape-memory alloys have the useful property of returning to their original shape after being greatly deformed. This process depends on the collective behavior of many small mineral grains in the metal. Using threedimensional x-ray diffraction, Sedmák et al. tracked over 15,000 grains in a nickel-titanium shape-memory alloy as it moved through this transformation,...

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 actuato...

This report introduces Shape Memory Alloys, describes properties of SMA as an actuator and introduces some available commercial SMA actuator products.

Despite the potential of these alloys and the amount of patents, successful industrial and commercial applications of Shape Memory Alloys (SMA) remain exceptions. This can be explained by the lack of design tools able to dimension correctly SMA elements because the non elastic behavior of SMA lead the classical method of design to be inefficient. Furthermore, this behavior is strongly dependent...

With the increased emphasis on both reliability and multifunctionality in the aerospace industry, active materials are fast becoming an enabling technology capturing the attention of an increasing number of engineers and scientists worldwide. This article reviews the class of active materials known as Shape Memory Alloys (SMAs), especially as implemented in aerospace applications. To begin, a g...

Constitutive laws for shape-memory alloys subjected to multiaxial loading, which are based on direct experimental observations, are generally not available in the literature. Accordingly, in the present work, tension–torsion tests are conducted on thin-walled tubes (thickness/radius ratio of 1:10) of the polycrystalline superelastic/shape-memory alloy Nitinol using various loading/unloading pat...