Project Description:

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.