Abstract

Results and conclusions of the analysis of a campaign of pull-off tests of single T-stiffened specimens are shown in this paper. The test intend to reproduce in a specimen the symmetrical local deformation shape that occurs in a stiffened panel during its postbuckling evolution. Four different groups have been considered combining two geometries and two stacking sequences for the skin and stringer. A total of 10 specimens have been tested. Tests were monitored with strain gauges. Visual inspections were performed during the process to detect the presence of debonding and/or delamination and to study the damage evolution. After the colapse, visual and microscopic analysis (optical and electronic) of the fracture surfaces were carried out. Inspections have shown the appearance of migrations of cracks from the skin-stiffening interface to delaminations between the first layers of the skin or vice versa. The effect that the different configurations of each specimen had on the onset and development of the damage has also been studied.