Robust inference of two-dimensional strain fields from diffraction-based measurements

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:444

Article

Hendriks, J. N.¹  Wensrich, C. M.¹  Wills, A.¹  Luzin, V.²  Gregg, A. W. T.¹ 

[1] Univ Newcastle, Sch Engn, Callaghan, NSW 2308, Australia

[2] ANSTO, Bragg Inst, Kirrawee, NSW 2232, Australia

关键词: Residual strain;    Neutron diffraction;    Gaussian processes;   

DOI  :  10.1016/j.nimb.2018.11.019

来源: Elsevier

【 摘 要 】

Diffraction-based methods have become an invaluable tool for the detailed assessment of residual strain and stress within experimental mechanics. These methods typically measure a component of the average strain within a gauge volume. It is common place to treat these measurements as point measurements and to interpolate and extrapolate their values over the region of interest. Such interpolations are not guaranteed to satisfy the physical properties of equilibrium and applied loading conditions. In this paper, we provide a numerically robust algorithm for inferring two dimensional, biaxial strain fields over a region of interest from diffraction-based measurements that satisfies equilibrium and any known loading conditions. By correctly treating the measurements as gauge volume averages rather than point-wise the algorithm has better performance when large gauge volumes and subsequently shorter beam-times are used. This algorithm is demonstrated on simulation and experimental data and compared to natural neighbour interpolation with linear extrapolation and is shown to provide a more accurate strain field.

【 授权许可】

Free