ESDU 75007 gives curves for the maximum direct stress at both the smaller and the larger hole boundaries as a function of their radii ratio and the centre distance. The locations of the maximum stresses are also given. Loading conditions are pure tension along@ at 45 degrees to@ and perpendicular to the line of centres@ and pure shear parallel and at 45 degrees to the line of centres. Although the curves were computed from a theory applying to an infinite plate@ no significant error will result from using them in a practical situation provided no plate edge is within four radii of either hole centre.
ESDU 75007-1975 history
1975ESDU 75007-1975 Geometric stress concentration factors: two adjacent unreinforced circular holes in infinite flat plates.