Article: Schuren JC, Wong SL, Dawson PR, Miller MP; (2014) Integrating Experiments and Simulations to Estimate Uncertainty in Lattice Strain Measurements. Journal of Strain Analysis for Engineering Design, 49(1):33-50
Abstract: The investigation of lattice strains has proven to be a viable method for probing the crystal level stress state in deforming polycrystalline samples. Building on the recent availability of high-rate X-ray detectors, we have developed a new technique that combines diffraction data with crystal-based finite element simulations to estimate the lattice strain uncertainty for each measurement. To estimate the uncertainty, we combine the probable number of crystals expected for each measurement with the simulated lattice strain standard deviation. Under this framework, the uncertainty is related not just to the number of diffracting crystals but also to the variability in the lattice strain between these crystals. An estimate of uncertainty for each measurement enables both the investigation of previously inaccessible phenomena where the lattice strain evolution is expectantly small and the application of lattice strain measurement techniques to materials with more complex microstructures. The new approach was demonstrated for an aluminum alloy 7075-T6 sample undergoing uniaxial tensile loading.