Effect of composite wrapping on the fracture behavior of the steel-lined hoop-wrapped cylinders

The steel-lined hoop-wrapped cylinders with internal axial semi-elliptical cracks in the cylindrical portion center of steel-liner have been modeled by a three dimensional finite element (FE) method. Crack front regions were modeled using singular elements, whereas the rest of the cylinder was modeled using twenty-node hexahedron elements. Not only the cylindrical body but also the neck and transition areas of the cylinder were considered in the modeling. The stress intensity factor, K I, and crack mouth opening displacement (CMOD) were calculated. The influence of the hoop-wrapped materials, the internal pressure and the crack sizes on the fracture behavior of the cylinder are discussed.