Application of plastic framing requirements for polar ships

A new International Association of Classification Societies (ICAS) standard for Polar Ship design, in the form of a Unified Requirement is being developed by an international committee with representatives from many classification societies and with the active participation of many polar nations. The framing structural requirements have been developed by a combination of analysis of existing rules and ships, finite element analysis and analytical solutions of plastic collapse mechanisms. This paper describes the use of the rule formulae in designs. The formulae contain interactions between shear and bending and give the designer options and flexibility in satisfying the strength requirements. Effective design requires knowledge of the effects, and the possible approaches to reach a satisfactory design.