Papers by Author: Ludek Heller

Abstract: In order to better understand the unique functional responses of shape memory alloys, improve the currently existing SMA modeling tools and used them beneficially in smart structure applications, it is desirable to investigate the deformation/transformation processes in these materials in action – i.e. under stress and temperature variation. In this work, an overview is presented on the applications of various recently developed or originally employed in-situ experimental methods and approaches to martensitic transformations in SMAs.

Abstract: Currently, thin NiTi wires have been considered for producing knitted and woven smart textiles with anticipated unique thermomechanical properties promising a wide range of new industrial applications. We propose a concept of NiTi tubular composite structures which enhances functional properties of single NiTi wires and offers new possibilities of their use. Such possibilities are provided by the combination of SMA properties with the geometrical architecture and properties of polymers incorporated into the tubular structures. Our study deals with the manufacture of the NiTi tubular composite structures and their thermomechanical properties under a uniaxial loading. Quasi-static properties and the strain-rate dependence are investigated in tension. We propose a way of producing novel SMA tubular composite structures. The designed composite samples exhibit thermomechanical properties characterized by the thermomechanical interaction between a NiTi tubular structure and incorporated polymers.