Diffraction stress factors calculated using a maximum entropy method

Diffraction-based stress analysis of textured materials depends on understanding the influence of the anisotropy of their elastic, plastic and thermal properties on the microscopic strain distribution. This is generally done by using simplifying assumptions for crystallite interactions to calculate tensorial stress factors or, in the case of very strong textures, by considering the material phase as a single crystal (crystallite group method). In this paper, we apply the micromechanical Maximum Entropy Method (MEM) to stress factor calculation, which marks its first use for materials with texture. The special feature of this approach is a native parametrization by the effective stiffness of the material, which allows the approach to be tailored to a macroscopically measurable sample property. We perform example stress analyses of cold-rolled copper, finding through validation with full-field simulations that the MEM yields accurate local strains even for materials with extremely sharp textures. In an example stress analysis of mildly textured cold-rolled ferritic steel, the accuracy of the approach compares favorably to the established Voigt, Reuss and self-consistent Eshelby-Kröner approaches. Compared to the latter, the method is also numerically efficient to calculate.