Superelastic Deformation of Adaptive Nano-Composites

Abstract

ABSTRACTAn adaptive composite containing a shape memory alloy as an active component is the subject of the paper. The elastically heterogeneous nano-composite containing ultra-thin layers of a passive material and thin layers of an active material is investigated in this paper. The superelastic modulus of the composite depends on the fraction of the active layer and can be negative if relative thickness of the active layer exceeds some critical value depending on the ratio between the elastic moduli of the layers and the characteristics of transformation. The negative superelastic modulus corresponds to the thermodynamic instability of superelastic deformation and results in stress-strain hysteresis. The relation between the elastic properties of the composite's components and relative thickness of the layers, which enable to stabilize the superelastic deformation, is obtained.