Tension and bending stress concentration factors in ‘U’, ‘V’, and opposed ‘U’–‘V’ notches

Abstract

An analytical and experimental study has been performed to determine the tension and bending stress concentration factors as a function of notch depth for ‘U'—‘V’, and opposed ‘U'—‘V’ notches. Accurate results are produced using quadrilateral finite elements where the edge-lengths in the notch region are less than 10 percent of the notch radius, and using strain gauges where the active gauge length is less than 1/3 the notch radius. Results are presented for single ‘U’ and ‘V’ notches that are outside the range of previously published studies. A detailed stress analysis of a single notched specimen revealed the presence of a tension stress concentration factor ( Kt > 1) and a bending stress reduction factor ( Kb < 1) on the un-notched side of the bar directly opposite the notch. An approximate method of determining stress concentration factors for opposed ‘U'—‘V’ notch geometries is presented.