Reliability Methods for Ship Structural Design (SHIPREL)

Duration: 01.10.1991-31.07.1995

Coordination: Instituto Superior Técnico

Partners: Bureau Veritas, Germanischer Lloyd, Registro Italiano Navale, Technical University of Denmark

Funding Entity: UE - Programa BRITE/EURAM

The objective of the project was the development of reliability based methods which are to be used for the design of ship structures, in particular by calibration of the safety factors in design rules. The project concentrates on the primary strength and thus it deals with the hull behaviour under longitudinal bending and aims at the design of the midship section, as representative of the parallel middle body. The approach taken in this project is to develop further the state of the art concerning the methods to predict the limit-states which are the basis of the reliability formulation. Roughly one third of it was devoted to the improvement of the load effect models, another third dealt with the strength assessment and only the last third dealt with the reliability analysis, reliability based design and code formulation. The SHIPREL project has explored a new way of formulating rules for ship structural design through the development of a methodology for rule development, by determining the methods to quantify the uncertainty in the variables, by performing reliability analysis of ship structures and by deriving partial safety factors for the design of the primary structure. Having identified the new formulations, they were applied to typical cases of containerships and tankers ascertaining how a coherent set of Rules were developed and applied to ships of varying load and structural behaviour. A set of simplified procedures and formulas have been developed to use in design for the prediction of design loads and for the assessment of the strength of primary structural components. Research software packages have also been developed to quantify loading, response and strength for the primary specific ship hull structures components. A methodology for code development and guidance notes for ship structural design has been established.

Project Team

Associated Publications