Stress Concentrations for Straight-Shank and Countersunk Holes in Plates Subjected to Tension, Bending, and Pin Loading

A three-dimensional stress-concentration analysis was conducted on straight-shank and countersunk (rivet) holes in a large plate subjected to various loading conditions. Three-dimensional nite-element analyses were performed with 20-node isoparametric elements. The plate material was assumed to be linear elastic and isotropic, with a Poisson's ratio of 0.3. Stress concentrations along the bore of the hole were computed for several ratios of hole radius to plate thickness (0.1 to 2.5) and ratios of countersink depth to plate thickness (0.25 to 1). The countersink angle was varied from 80 to 100 in some typical cases, but the angle was held constant at 100 for most cases. For straight-shank holes, three types of loading were considered: remote tension, remote bending, and wedge loading in the hole. Results for remote tension and wedge loading were used to estimate stress concentrations for simulated rivet or pin loading. For countersunk holes, only remote tension and bending were considered. Based on the nite-element results, stress-concentration equations were developed. Whenever possible, the present resultswere compared with other numerical solutions and experimental results from the literature.