Tomographic Reconstruction of Two-Dimensional Residual Strain Fields from Bragg-Edge Neutron Imaging

Abstract

Bragg-edge strain imaging from energy-resolved neutron transmission measurements poses an interesting tomography problem. The solution to this problem will allow the reconstruction of detailed triaxial stress and strain distributions within polycrystalline solids from sets of Bragg-edge strain images. Work over the last decade has provided some solutions for a limited number of special cases. In this paper, we provide a general approach to reconstruction of an arbitrary system based on a least squares process constrained by equilibrium. This approach is developed in two- dimensions before being demonstrated experimentally on two samples using the RADEN instrument at the J-PARC spallation neutron source in Japan. Validation of the resulting reconstructions is provided through a comparison to conventional constant wavelength strain measurements carried out on the KOWARI engineering diffractometer within ANSTO in Australia. The paper concludes with a discussion on the range of problems to be addressed in a three-dimensional implementation.

References in corpus (2)

• Probabilistic modelling and reconstruction of strain
• Bragg-Edge Elastic Strain Tomography for in situ Systems from Energy-Resolved Neutron Transmission Imaging

Cited by in corpus (7)

• Linearly Constrained Neural Networks
• Tomographic Reconstruction of Triaxial Strain Fields from Bragg-Edge Neutron Imaging
• Implementation of Traction Constraints in Bragg-edge Neutron Transmission Strain Tomography
• Neutron Transmission Strain Tomography for Non-Constant Stress-Free Lattice Spacing
• Neutron Diffraction Strain Tomography: Demonstration and Proof-of-Concept
• Radial Basis Functions and Improved Hyperparameter Optimisation for Gaussian Process Strain Estimation
• Bayesian Non-parametric Bragg-edge Fitting for Neutron Transmission Strain Imaging