Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Macroscopic modeling of shape memory alloys under nonproportional thermomechanical loadings
 Journal of Intelligent Material Systems and Structures 13 (2002), No.12, pp.825836 ISSN: 1045389X ISSN: 15308138 

 English 
 Journal Article 
 Fraunhofer IFAM () Fraunhofer ITWM () 
Abstract
A new continuum model for the description of the general mechanical behavior of polycrystalline Shape Memory Alloys (SMA) is introduced in order to represent some particular 3Deffects not described by usual plasticitylike macroscopic models (e.g., reorientation under general loadings). The model describes the oneway and the pseudoelasticity shape memory effects as well as their transient behavior under reorientation of the martensite by arbitrary thermomechanical loadings. The main idea for the description of phase change and martensite reorientation consists of the assumption that the driving forces of the phase transformation depend on both the actual stress state and the transformation induced strain (TIS) tensor. In order to describe the change of the martensite structure both, the TIS as a tensorial internal variable together with a scalar valued variable which describes the phase fraction of thermally induced martensite, are used. The evolution of the TIS tensor is described by a new evolution equation without plastic analogy. The problem of modeling the evolution direction and the thermodynamical consistency are discussed in details.