Cyclic multiaxial behavior modeling of Shape Memory Alloys

Abstract : New phenomenological approaches in modeling the behavior of SMAs are needed to account for their complex response under multiaxial loading. The effect of anisotropy induces a dependence of their inelastic behavior to the direction of the loading for superelastic cases. Martensitic reorientation affects drastically material response under non-proportional loading. Repeated loading also alters certain material properties. The goal of this study is to propose a new robust thermodynamic constitutive model for SMAs with focus on equiatomic NiTi compositions to capture anisotropic martensitic transformation and reorientation of martensitic variants, always taking in mind the strong thermomechanical coupling. A new mathematical approach is introduced to account for the anisotropy of stresses and the evolution of inelastic strains during forward transformation caused by the forming conditions of SMA structures. This method is evaluated by utilizing stress-strain curves resulting from proportional loading simulated with a micromechanical model. A phenomenological thermodynamic model considering especially martensitic reorientation and exhibiting the strong thermomechanical coupling is developed. It is implemented on a numerical platform in C++, SMART, and evaluated by simulating existing non-proportional experiments. Complex structures are also simulated using Finite Element Analysis. The last part of this work concerns the experimental study of the effects of cyclic loading to the evolution of residual strain and transformation threshold of NiTi under uniaxial and biaxial testing.
Complete list of metadatas

Cited literature [202 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-01344616
Contributor : Abes Star <>
Submitted on : Tuesday, July 12, 2016 - 11:53:06 AM
Last modification on : Tuesday, May 28, 2019 - 3:40:13 PM

File

CHATZIATHANASIOU.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01344616, version 1

Citation

Dimitrios Chatziathanasiou. Cyclic multiaxial behavior modeling of Shape Memory Alloys. Mechanics of materials [physics.class-ph]. Ecole nationale supérieure d'arts et métiers - ENSAM, 2016. English. ⟨NNT : 2016ENAM0015⟩. ⟨tel-01344616⟩

Share

Metrics

Record views

683

Files downloads

966