Application of the Relaxed Free Energy of Mixing to Problems in Shape Memory Alloy Simulation

Recent theoretical advances in the development of functional representations for the free energy of mixing associated with solid-solid phase transformations has made possible the development of a new class of constitutive models based directly on bounds to the relaxed free energy. The present work, which continues that of Govindjee et al. (2002) and Hall and Govindjee (2002), demonstrates the application of the theory to the simulation of the complex behavior exhibited by shape memory alloys. The first three case studies undertaken herein support the validity of the theoretical approach by analyzing subtle aspects of the physics associated with such phase transformations. The final simulation, a torsion tube under combined loading, provides impetus for future experimental and theoretical advancements.