3-D Finite Element Analysis of Indentation Recovery due to the Shape Memory Effect

The potential use of Shape Memory Alloys (SMAs) as micro-actuators promotes study of the behaviors of these materials at small length scales. The recovery of micro-indentations due to the shape memory effect has recently become an area of particular interest. Experimental observation indicates promising microactuation ability in SMAs subject to indentation. In order to better understand the mechanisms underlying this phenomenon, 3D Finite Element Analysis incorporating a new SMA transformation-plastic yield constitutive model is used to simulate a unique experimental indentation procedure. This process involves the indentation of an SMA material and the planarization of the material surface to remove all visible traces of the indent region; upon subsequent heating, a protrusion (exdent) is created in the indented zone. Key results of an analysis that simulates this experimental procedure are discussed, along with possibilities for future work.