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 (K_t > 1) and a bending stress reduction factor (K_b < 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.