Buckling of Shape Memory Alloy Columns

Abstract

The research described in this paper grew from the serendipitous discovery of the TD (Twinning Deformation) effect, which was discovered by the first author. The experiment involved a Shape Memory Alloy (SMA) column that was plastically deformed into a cosine wave. The column was then compressed from either end. As the compressive force was increased, the column became straighter. The curved column-buckling load is the same as that of the straight one. In this research, numerical analysis was performed on the distributions of stress and deformation of the SMA beams under compression. Analysis of the anti-buckling capability involves a theoretical treatment of Non-Euler buckling. One way of explaining the buckling mechanism is to consider the moment-deflection ratio as a spring constant. The result of this calculation is in good agreement with those obtained for experimental buckling loads. And based on the same analysis, the neutral fiber (or structural center) of the curved column was also calculated.