Investigations Into the Physical Mechanisms That Facilitate Transformation Hysteresis in Shape Memory Alloys

Influences of energy dissipative mechanisms are rationalized using a theoretical approach which combines micro-mechanics and thermodynamics into a thermo-mechanical framework. Models are formulated for the thermal and stress hysteresis based on a thermo-mechanical framework so as to shed light into differential hysteresis magnitudes. Current theoretical formulations consider energy dissipation from a phenomenological point view and satisfy the second law of thermodynamics by considering a dissipative potential. In the current study, an earlier thermo-mechanical formulation is advanced beyond phenomenological considerations to include the effects of micro-scale plasticity. With this, the hysteresis models can account for energy dissipation resulting from strain energy relaxation. The current modeling approach provides intuitive predictions of the experimentally observed behavior particularly a growing hysteresis with increasing stress for NiTi alloys.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Hamilton, Reginald F.

Contributors dc:contributor

• Sehitoglu, Huseyin

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI3337782

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83915