Tech Briefs

Shape-Memory Alloy (SMA) material model

In ADINA 8.3, a new shape-memory alloy (SMA) material model is available for the 1-D truss element, the 2-D and 3-D solid elements, and the isobeam element. The SMA material model simulates the superelastic and shape-memory effects of shape-memory alloys which are widely used in orthodontic wires, blood-vessel stents, etc. The material model takes into account the transformation from austenite to martensite. The effects of temperature can also be included.

Just as an illustration of the material behavior, 1-D numerical results, which are of course equal to the theoretical model results, are given in the above figure.

We demonstrate this new model with the three-point bending test solved also by Auricchio and Sacco, see ref. [1]. Twelve 20-node 3-D solid elements are used to perform the analysis. The figure below shows a band plot of the detwinned martensite fraction at maximum deflection, and the following graph is a plot of the load-displacement curves. The hysteresis resulting from the material transformation, reverse transformation and the complete recovery of deformation can be seen from the graph, as well as the reasonable agreement of the ADINA results with the data given in ref. [1].

Ref. [1]

Auricchio, F. and Sacco, E.: A temperature-dependent beam for shape-memory alloys: constitutive modelling, finite-element implementation and numerical simulation. Computer Methods In Applied Mechanics and Engineering, 174(1999), pp. 171-190.