Elastic stress field solution of helical dislocation lines in BCC Iron: A three-dimensional anisotropic linear elasticity study

Mutual interaction among microstructural elements, such as dislocations or point defects, through elastic fields plays an important role in understanding the dynamic evolution of microstructures in materials. For example, the ability of a helical dislocation to absorb extra point defects relies on the distribution of vacancy or interstitial around the helical dislocation line, which is determined by the elastic stress tensor. Therefore, to understand the kinetics and thermodynamics of crystallographic defects far from their statistical equilibrium, e.g., under irradiation, one needs to get an insight into the elastic stress field associated with helical dislocations. Using anisotropic linear elasticity theory, we investigate the elastic stress field induced by the helical dislocation line. Helical dislocations generate significant normal stress in the direction parallel to their axis within the helix region, while the other stress components are negligibly small. Furthermore, we elucidate the effect of geometrical parameters of helical structure, such as pitch length, diameter, and chirality, on the magnitude and distribution of the stress field. Atomistic simulation is also conducted to verify the elastic field modeling results further.