Post Buckling Behavior Of Stiffened Composite Plates Under Shear Loading

Thin-walled stiffened composite plate is widely applied in project. For example, airfoil of plane, surface of empennage, plate of airframe and so on. Failure mode commonly is buckling, when structure get compress, shear, bending loading in plane. In fact, thin-walled stiffened composite plate under buckling do not fail, and these structure can still have a reasonable load-carrying capacity, which is generally named post-buckling strength. Thus in order to control structure failure and assure security of structure, it is necessary to investigate the buckling and post-buckling behavior characteristic.First of all, buckling test in shear was investigated for thin-walled stiffened composite plate. The experimental results showed that buckling load of structure was 21.99KN and failure load was 95.40KN. The post-buckling strength of structure was biggish.In the next place, impact test was investigated for thin-walled stiffened composite plate. The relation between impact energy and damage area was found. Then, shear test was carried out for impacted specimen. The experimental results showed that buckling load of impacted specimen descend less than undamaged specimen and failure load of impacted specimen descend more than undamaged. Shear test also was carried out for repaired specimen. Repaired specimens were through hole repaired specimen and adhesive failure repaired specimen. The experimental results showed that the performance of these repaired specimens was preferable.Finite element method was also used to analyze the buckling behavior of that composite structure. Analysis results reveal buckling mode and buckling loading of finite element analysis are accordable with experimental results. Experiment results also reveal that stiffened thin-walled composite plate can bear greater load after buckling. The influences of the continuity of rib and the direction of shear load on the buckling load were also investigated.