A simulation model for stress measurements in notched test specimens by x-ray diffraction

Abstract

An analytical model was developed to simulate the stress state of notched tensile specimens. Actual experiments are being carried out by other investigators to study the relaxation of residual stresses in specimens containing stress raisers. In the present work, the stress state developed in notched tensile specimens was assessed by determining the response of the stress state in the form of x-ray line profiles; this is useful in the understanding and measurement of effects due to such stress states obtained in actual experiments. The theoretical relationship between the stress gradient and the depth of penetration of the x-ray beam at the edge of a notch tensile specimen was also studied. In addition, the effect of changes in the radius of curvature of the notch-tip on errors in measured stress values is also considered. Furthermore, a description of the state-of-the-art x-ray system being used in the experimental work is also included.