A finite-deformation-based constitutive model for high-temperature shape-memory alloys. (June 2017)

• Record Type: Journal Article
• Authors: Sakhaei, Amir Hosein; Thamburaja, Prakash
• Is Part Of: Mechanics of materials. Volume 109(2017)
• Page Start: 114
• Page End: 134
• Publication Date: 2017-06
• Subjects: High temperature shape memory alloy -- Constitutive behavior -- Finite strain -- Finite-element simulation; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2017.03.004
• Languages: English
• ISSNs: 0167-6636

Abstract

Highlights: A thermo-mechanically-coupled, finite-deformation, isotropic-plasticity-based constitutive model to describe the austenite-martensite phase transformations, viscoplasticity and transformation-induced plasticity in high-temperature shape-memory alloys has been developed in a thermodynamically-consistent manner. The constitutive model has been implemented into the commercially-available Abaqus/Explicit (2016) finite-element program through the user-material (VUMAT) subroutine interface. The finite-deformation-version of the constitutive model is able to predict the effect of geometric stiffening effects unlike small-strain-based models for structural applications which exhibit large deformations. Abstract: In this work, we develop a coupled thermo-mechanical, isotropic-plasticity, finite-deformation-based constitutive model for high-temperature shape memory alloys (HTSMAs). This constitutive model is capable of describing austenite-martensite phase transformations, rate-dependent plasticity (creep) in the austenitic phase, and also transformation-induced plasticity (TRIP) due to phase transformations between the austenitic and martensitic phase. The constitutive model was also implemented into a commercially-available finite-element program through a user-material subroutine interface. By using suitably valued material parameters in the constitutive model, we show that the output obtained from our finite-element simulations are able to accurately match the experimental strain-temperature cycling data for a ternary high-temperature shape memory alloy (Ti-Ni-Pd) under various applied stresses. We also show through finite-element simulations that for particular boundary-value problems of practical/engineering significance, the usage of a finite-strain-based constitutive theory gives vastly different results when compared to using a small-strain-based constitutive theory.