Experimental study on strength of non-stitched/stitched skin-to-stiffener structures

Stitch is an important way to enhance fracture toughness and connection. In order to validate its enhancement effect comparing to traditional bond structures, two groups of stitched/non-stitched composite T-shaped and L-shaped skin-to-stiffener performs were designed, and check experiment on the strength of non-stitched/stitched skin-to-stiffener structures, loaded in tensile pull-off, was performed. The results show that the stitched L-shaped specimen strength increased by 93.4% averagely, while the stitched T-shaped specimen did not improve. Reasons for the case were analyzed basing on experimental phenomenon.