The development of improved attachment methods for stiffening frames on large grp panels

A current design of top-hat stiffened grp ship hull uses through-bolts in the stiffener flanges to improve the through -thickness strength of the bond of the stiffener frame to the hull. This research programme investigated lower cost substitutes for the through-bolting procedure. Two approaches were considered, the use of an alternative mechanical fastener and a change in the lamination methods and materials used for stiffener fabrication. The performance of the various fabrication techniques was compared by pull-off testing of top-hat stiffened sections.