UTA Department of Mathematics

Applied Mathematics Seminar

Date/Time/Room: Thursday (4/11/2002) at 2:00pm in 487 Pickard Hall

Speaker: Pavlin Entchev, Department of Aerospace Engineering, Texas A&M University

``The Effect of Transformation-Induced Plasticity on the Behavior of Shape Memory Alloys''

Abstract: Shape Memory Alloys (SMAs) are metallic alloys which can recover permanent strains when they are heated above a certain temperature. The key characteristic of all SMAs is the occurrence of a martensitic phase transformation. The artensitic transformation is a shear-dominant diffusionless solid-state phase transformation occurring by nucleation and growth of the martensitic phase from a parent austenitic phase. This phase transformation is accompanied with the development of large (on the order of 5%) recoverable transformation strain. In addition to the development of transformation strain the accumulation of permanent plastic strain has been observed in the SMAs under cyclic loading.

Due to the inherent non-linear behavior of the SMAs their modeling has presented many challenges and has been a topic of a number of research publications. The current work is devoted to the three-dimensional constitutive modeling of SMAs under cyclic loading. The evolution of both transformation and plastic strains is taken into account. A detailed description of the model will be given. In addition, the numerical implementation of the model will be discussed. The results will be compared with the available experimental data.