Influence of Cyclic Loading on Inhomogeneous Deformation Behavior Arising in NiTi Shape Memory Alloy Plate

The aim of present paper is the investigation of relationship between inhomogeneous deformation behavior and macroscopic deformation behavior arising in SMA during cyclic loadings. Firstly, a test system was constructed on the basis of Digital Image Correlation in order to measure inhomogeneous deformation behavior. Secondary, measurements of the inhomogeneous deformation behavior (local strain distribution) arising in 50.5Ni49.5Ti plate were tried during cyclic tensile loading– unloading in the region of pseudoelastic temperature. From some results, it is seen that the inhomogeneous deformation behavior sensitively changes according to the state of loadings (i.e., number of cycle, history of loading and so on). Also, the macroscopic deformation behavior for SMAs is strongly affected by the inhomogeneous deformation behavior. It is very important for application of SMA to investigate the relationship between macroscopic deformation behavior and inhomogeneous deformation behavior.