Effect of spatial variation of stress-free lattice spacings on measured residual stresses

No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
SAGE Publications
When neutron diffraction is used to measure residual stresses, estimates of the unstressed lattice spacing (d(0)) are often required. These are generally measured on a sample that is considered representative of the component. In the case of welded samples, the possibility of variation in weld shape between the d(0) sample and the area where stresses are determined must be taken into account. To assess this, d(0) values are measured on an area considered representative of the sample, and then are re-measured on a sample cut from the actual strain measurement plane. The residual stresses are re-calculated with these new d(0) values and the results compared to those based on the initial d(0) measurement. Methods of estimating these errors are discussed. The errors in residual stress that arise from the spatial variation of d(0) values are greater than the commonly reported peak fitting errors. These errors can be estimated and should be included in the reported residual stress measurements. Cutting a d(0) sample from the measurement plane makes this a destructive technique. © 2011, SAGE Publications
Welding, Residual stresses, Neutron diffraction, Strains, Crystal lattices, Peaks
Law, M., Luzin, V. (2011). Effect of spatial variation of stress-free lattice spacings on measured residual stresses. Journal of Strain Analysis for Engineering Design, 46(8), 837-841. doi:10.1177/0309324711413648