Application of thermodynamic dislocation theory to BCC-Crystals

Abstract

Thermomechanical response of materials may now be accurately described as a result of significant advancements in theoretical approaches and models, as well as numerical simulations over the last two decades. Our work presents the theory of dislocation-mediated plasticity which is originally presented by Langer, Bouchbinder, and Lookman (2010) and its modified version called thermodynamic dislocation theory . We demonstrate that the theory can match the stress-strain curves of body-centered cubic crystals niobium, tantalum, tungsten, and vanadium over a wide range of temperatures and strain rates by employing a restricted set of physics-based material parameters that are found by the large scale least squares analysis.