Stress- intensity factor for a cracked sheet with riveted and uniformly spaced stringers

The stress- intensity factor and forces in the most highly loaded rivet and stringer were calculated for a cracked sheet with riveted and uniformly spaced stringers. Two symmetrical cases of crack location were considered - the case of a crack extending equally on both sides of a stringer and the case of a crack equally on both sides of a point midway between two stringers. The complete results are presented on design graphs for systematic variations of crack length, rivet spacing, stringer spacing, and stringer stiffness. The results show that the stress- intensity factor for the stiffened sheet is significantly lesshan that for an unstiffened sheet, except for crack lengths much less than the stringer spacing. Also, the forces in the most highly loaded stringer and rivet asymptotically approach limiting values for increasing crack length. The stress- intensity factor and the limiting values of the stringer and rivet forces are smaller for stiffer or more closely spaced stringers or for more closely spaced rivets.