Effect of a Stringer on the Stress Concentration Due to a Crack in a Thin Sheet

A coefficient is obtained for determining the effect of a reinforcing stringer on the stress concentration factor at the tip of a crack in a thin sheet. The results are given for the case on which the stringer is intact and for the case in which the stringer is broken. In the first case the stress concentration factor for the stringer is given

A variational theorem for creep with applications to plates and columns

A variational theorem is presented for a body undergoing creep. Solutions to problems of the creep behavior of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems

NACA Technical Notes

From Summary: "A coefficient is obtained for determining the effect of reinforcing stringer on the stress concentration factor at the tip of a crack in a thin sheet. The results are given for the case in which the stringer is intact and for the case in which the stringer is broken. In the first case the stress concentration factor for the stringer is also given.

NACA Technical Notes

Report presenting a method for obtaining influence coefficients for thin low-aspect-ratio wings of built-up construction. Symmetric and anti-symmetric load-support conditions are considered. A simple method is given for taking account of attachment to a flexible fuselage

NACA Technical Reports

"A chart in terms of nondimensional parameters is presented for the theoretical critical stress in torsion of simply supported cylinders stiffened by identical equally spaced rings of zero torsional stiffness. The results are obtained by solving the equation of equilibrium by means of the Galerkin method. Comparison of the theoretical results with experimental results indicates that ring-stiffened cylinders buckle, on the average, at a buckling stress about 15 percent below the theoretical buckling stress" (p. 1)

NACA Technical Reports

A variational theorem is presented for a body undergoing creep. Solutions to problems of the creep behavior of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems