ADVANCE Fellows Award: Thermomechanical Models of Martensitic Phase Transitions

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

DMS Award Abstract Award #: 0137634 Principal Investigator: Vainchtein, Anna Institution: University of Pittsburgh NSF program: Infrastructure Title: ADVANCE Fellows Award: Thermomechanical models of martensitic phase transitions This proposal is concerned with physically-motivated thermomechanical models of materials, such as shape memory alloys, that undergo martensitic phase transitions. These materials are characterized by a strong coupling between temperature and deformation fields and exhibit markedly hysteretic behavior when subjected to cyclic mechanical loading. The origin of hysteresis, kinetics of phase boundaries and thermomechanical interactions are important open problems in modeling of martensitic phase transitions. The proposal includes several continuum models that account for both inertia and thermal effects. The important components of the models are nonconvex elastic energy, latent heat of transformation and time-dependent loading. The main goal is to develop a model capable of capturing the most significant experimental observations, such as size and features of hysteresis loops, volume fractions of material phases and details of interface dynamics. Important phenomena such as serrated hysteresis, inner loops, thermal trapping and evolution of twin microstructures will be investigated. The results of the proposed work will be important for the emerging applications of shape memory materials, such as damage, vibration and acoustic transmission control in composite structures. By advancing the scientific understanding of the dissipative properties of shape memory alloys, this research will potentially contribute toward the development of innovative seismic damping devices for buildings and bridges. The educational component of the proposed work includes involving graduate and advanced undergraduate students in the research program, developing new courses, creating an outreach middle-school program and mentoring women graduate students.