Impact and compression after impact behavior of single-stiffener composite panels

The purpose of this paper was to investigate the damage tolerance of single-stiffener panels. The impact response and the influence of impact damage on compression behavior were studied. Barely visible impact damage (BVID) was introduced to the stiffener flange tip on the smooth side. By applications of visual inspections and C-scan, massive damage was detected. After the impact experiment, compression tests were carried on the intact specimens and impacted specimens. The experimental results reveal that impact damage has no significant effect on the buckling mode. but decreases the buckling load by about 10%. The results also show that impact damage has an important influence on the compression failure mechanism. Under the compressive loading, impact damage propagates inside the skin after the buckling, which is a trigger for final fracture of damaged stiffened panels. Consequently, the impact damage causes a dramatical decrease in the failure load by 34%, approximately.