The effects of delamination deficiencies on compressive mechanical properties of reinforced composite skin structures

In this study, the compressive properties and failure mode of reinforced composite skin structures having different delamination deficiencies were investigated systematically. Different kinds of delamination deficiencies were presented at specific locations in the specimens. The compressive mechanical properties of the materials were performed by axial compression testing, and strain distribution in different parts of the specimen and bearing capacity were monitored during the compressing processes. The ultimate compression bearing capacity, the failure mode and the expansion of internal damage were investigated as well. Results showed that the existence of delamination deficiencies have effects on the ultimate loading capacity of the specimens in different degree, in which the influence of delamination deficiencies in the skin is the most serious. Comparing with the specimen without deficiencies, the ultimate load-carrying capacity of the specimen with delamination deficiencies in the skin and in the stiffener under compressive load reduced by 38.58% and 22.34%, respectively. The failure modes of specimens with and without delamination deficiencies are similar. Compression failure is the main form of fracture for the stiffener, and the skin having different degree of buckling and delamination.