Fabrication of Stiffened Composite Plates With Integrated Longitudinal and Transverse Stiffeners

Stiffened steel plates are commonly used in the deck of ships and offshore oil platforms and predominantly subjected to both in-plane and out-of-plane loads. Due to high strength to weight ratio and stiffness to weight ratio, and excellent corrosion resistance, stiffened composite plates are used as an alternative to stiffened steel plates. Stiffened composite plates are fabricated by producing flange plates and stiffeners separately and attaching the stiffeners by adhesive bonding to the flange plate, which leads to debonding mode of failure before attaining its ultimate strength. The debonding mode of failure of stiffeners can be avoided by integrating the stiffeners into the flange plate during fabrication. A novel procedure has been developed in this study for the fabrication of stiffened composite plates to integrate both the longitudinal and transverse stiffeners into the flange plate during the layup process. The design of stiffened composite plates, mould, layup sequence, integrating the longitudinal and transverse stiffeners to the flange plate and at the junctions of longitudinal and transverse stiffeners, and field applications are briefly presented in this paper.