The core strength of the Shape Memory Alloy Research Team is the development and
implementation of constitutive models for SMAs. We have traditionally focused on three-dimensional
phenomenological modeling, and often seek to capture behaviors not considered by other groups. For
examples, where early models were developed for isothermal psuedoelasticity, Texas A&M researchers focused
on thermal actuation. Many bulk effects are considered in the current models, including transformation-induced plasticity (TRIP),
smooth transformation hardening, thermally-induced transformation strain magnitudes that vary with load level,
plastic yielding, viscoplastic creep and relaxation, etc. We are also working to characterize and model the
behavior of High Temperature Shape Memory Alloys (HTSMAs) by extending previously developed constitutive
models in order to account for viscoplastic phenomena occuring at the high temperature environments, identifying
the effect of creep mechanismsm, activated at high temperatures, in the actuation performance of HTSMA actuators,
and investigating the interaction between transformation, TRIP and viscoplasticity. These models have been
applied to the design and analysis of engineering applications ranging from the biomedical to the aerospace
to the oil exploration industries.
People Involved with
Constitutive Model Development:
Darren Hartl, Ph.D.
Dimitris Lagoudas, Ph.D.
George Chatzigeoriou, Ph.D.
Parikshith Kumar, Ph.D.
Yves Chemisky, Ph.D.