Local strain distribution arising in shape memory alloy composite subjected to thermal loading

Abstract

The main purpose of the present research is the measurement of local strain distributions generated in a shape memory alloy composite (SMAC) under thermal loading. In the present study, firstly, the test system is constructed on the basis of Digital Image Correlation (D.I.C.) in order to measure local strains all over the surface of object. Then, local strain distributions generated in SMAC are measured under heating. Results in present study are us follows: (1) Longitudinal local strain reveals inhomogeneous deformation behavior during austenite transformation of SMA fiber, and shows distribution along to x and y direction after austenite transformation. Also, we can see that the state of distribution is different between x and y directions after austenite transformation. (2) Lateral local strain begins to generate around fiber during austenite transformation of SMA, and shows distribution along to only y direction after austenite transformation. This distribution is caused by thermal expansion of matrix. (3) Shearing local strain begins to generate at fiber edge during austenite transformation of SMA fiber, and shows distribution along to x and y direction after austenite transformation. © 2006 The Japan Institute of Metals.