Strength Bond Offshore Assessing the strength of bonded repairs

For ships and offshore units with a steel structure, corrosion is a constant threat and maintenance an ongoing challenge, characterized by a long, costly repair process. One solution being developed is bonding a composite reinforcement patch to damaged structures, which stands to limit costs, optimize maintenance and improve asset design.

Strength Bond Offshore is a joint industry project (JIP) with two objectives. The first is to study the strength prediction and fatigue of composite repairs for corroded steel plates, with a focus on identifying the best methodology and numerical tools for performing strength prediction. The second is to gather data on typical composite repairs and improve the knowledge of all consortium partners.

Project goals

Produce clear, practical and industrially applicable design guidance for assessing bonded repairs
Develop a robust methodology for strength analysis and fatigue prediction
Assess key numerical and design tools and produce best-practice guidelines for using them to perform strength analysis
Refine test set-ups and methodology for characterization of the key data too feed numerical design tools
Develop manufacturing protocols and quality checks for bonded repair materials

Collaborating with industry experts

The Strength Bond Offshore JIP brings together major oil players, naval shipyards, composite manufacturers, bonded repair providers, software providers, specialist laboratories and classification societies. Consortium participants include TOTAL, Petrobras, Naval Group, InfraCore Company, Siemens, ColdPad, with collaboration from the University Gustave Eiffel (SMC and SII laboratories) and Sigmeo.

Assessing strength qualification

Engineers face a basic problem when assessing strength qualification: general tests for composite bonded repairs are insufficiently specific to hybrid metal composite design. Strength Bond Offshore is developing guidelines for design verification and strength prediction specific to offshore units, improving reliability and safety, and optimizing the design process.

Determining asset repair durability

Determining the durability of bonded composite repairs requires the ability predict repair strength in the short- prior to analyse long-term. Bureau Veritas is working on several research projects that concern asset ageing and durability, including Qualify, Real Tide, Ramsses and Fibreship. Strength Bond aims to obtain conclusive results on strength prediction, then combine these findings with those from projects on ageing to understand the life cycle durability of bonded repairs.

Evaluating key design tools

A variety of standard designs for marine and offshore unit repairs will be tested as part of this project, creating a benchmark of numerical design tools. Infracore Company is manufacturing composite parts to professional and industrial standards, and these prototypes will be tested at UGE using high resolution optical fibres. This will allow the consortium to single out robust strength prediction tools and develop corresponding guidelines for the assessment of composite repairs design.

Developing manufacturing standards

Strength Bond Offshore is putting a focus on protocol definition and quality checks throughout the manufacturing process. Sample repairs built to scale will be developed as part of the project, allowing for the evaluation of reliability of manufacturing protocols.

More information? Contact us:

jip.strengthbondoffshore@bureauveritas.com

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