Curvature Effects on Stress Concentrations at Reinforced Circular Holes

The primary purposes of this paper are: first, to present a summary of the results of recent investigations into the effects of the curvature on the stress conditions at circular boundaries in shallow cylindrical shells; and second, to apply these results, in the form of influence coefficients at the circular boundary in the shell, to a more complex problem of practical importance which might be encountered in the design of advanced marine or aerospace vehicles. When the boundary conditions at the shell edge specify either the stresses, deformations, or mixtures of both, solutions are obtained through direct use of the influence coefficients. When the stresses and deformations are linked elastically, as exemplified by problems concerning reinforced holes, solutions are more complex in nature. Results for stresses at the intersection of a shell with a flat circular reinforcement are presented here as a function of shell curvature for particular material and geometric properties of the shell and reinforcement. Also, the formulation of the problem where both reinforcement and shell are curved is included.