Objective
Through the development of several models, the system aims to bring practical and economic values to the analysis of structural safety in the offshore industry. The models can be used by engineers to demonstrate the effectiveness of a design, assess the strengths and weaknesses of a design, and aid the inspection process.
Probabilistic modelling of environmental loads, pile foundations, tubular member behaviour, and fatigue/fracture behaviour of tubular joints; the development of efficient methods for performing global structural analysis; the development of improved methods for structural system reliability analysis and the development of methods for structural optimization under reliability constraints are incorporated in RASOS.
A database has been set up for compiling and analysing inspection data, both for new projects and maintenance and repair of existing ones.
RASOS may be used for code development and evaluation of partial safety factors; design or assessment of specific structures; inspection and repair decisions for existing structures; parametric studies and structural optimization.
The aim of the project was to develop probability based design methods for use by the engineering profession in the offshore industry. The project has dealt with the development of methods and software for calculating the probability of failure of jacket type structures for a variety of member failure modes (plasticity, buckling, fatigue). The effect of redundancy of the structures can be investigated by calculating the combined probability of sequences of member (end) failures, either automatically or user specified. For plasticity limit states advanced Monte Carlo options are available. Particular aspects of the probabilistic analysis of offshore structures included: probabilistic modelling of environmental loads, pile foundations, tubular member behaviour and fatigue/fracture behaviour of tubular joints; development of efficient methods for performing global structural analysis; development of improved methods for structural system reliability analysis and development of methods for structural optimization under reliability constraints; and application of probabilistic methods in the fields of inspection, maintenance and repair. These objectives have been largely fulfilled and in some areas the developments have been more significant than was originally considered possible. In the case of inspection, maintenance and repair, a database system has been developed which can be used for compiling and analyzing inspection data. All the models and methods have been incorporated into a computer based reliability analysis system for offshore structures (RASOS). This is supported by extensive documentation comprising users' manuals, programmers' manuals and theoretical manuals. For use with RASOS a recommended set of models for random variables has been set up.
THE PROJECT HAS THE GENERAL OBJECTIVE OF PROMOTING THE USE OF PROBABILISTIC MET HODS BY THE ENGINEERING PROFESSION AND SPECIFIC OBJECTIVES IN TERMS OF THE DEVE LOPMENT OF CERTAIN AREAS IN PROBABILISTIC ANALYSIS OF OFFSHORE STUCTURES.
THESE SPECIFIC AREAS ARE:
1. MODELLING OF BASIC VARIABLES AND MEMBER FAILURE MECHANISMS 2. MODELLING OF THE BEHAVIOUR OF DAMAGED MEMBERS
3. METHODS TO CALCULATE THE OVERALL SYSTEM RELIABILITY
4. APPLICATION OF PROBABILISTIC METHODS IN THE FIELDS OF INSPECTION, MAINTENANC E AND REPAIR.
THE PROJECT WILL RESULT IN OPERATIONAL COMPUTER PROGRAMMES FOR THE CALCULATION OF THE SYSTEM RELIABILITY AND A NUMBER OF REPORTS TO GUIDE THE USER IN VARIOUS CIRCUMSTANCES.
Fields of science
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
LONDON
United Kingdom