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Improved Fatigue Life of Welded Jacket Connections (JaCo)

The JaCo project aims to cut the cost of offshore wind by optimising the design of jacket foundations through improved fatigue standards and validation of faster testing and fabrication methods. 

The move to deeper waters and larger wind turbines means there will be greater numbers of jackets and floating foundation used in offshore wind. Understanding the fatigue life of these large, welded structures is critical to optimising their design and longevity.

The OWA JaCo project conducted accelerated fatigue testing of full-scale welded nodes to better understand how modern welding practices can be used to inform the design of these structures. The JaCo project aimed to cut the cost of offshore wind through technological advances that revolutionise and optimize jacket node design and fabrication.

Extensive large-scale testing is needed to provide a sufficient data basis for supporting the existing guidance or the development of new fatigue curves, and to compare robotic with manual welding techniques.

The objectives of the project were:

  • Validation of S-N curves and fatigue classes for welded jacket nodes through extensive stress testing, with the goal of enabling a reduction in weight, CAPEX and installation costs.
  • Validation of robotic against manual welding through extensive testing of a large number of manual and automatic welded nodes
  • Industrialise jacket fabrication and enhance reproducible quality by automated processes
  • Validate faster testing methods using (innovative) resonance techniques rather than (traditional) hydraulic processes

In the JaCo project, the Belgian research institute OCAS is using an novel technique to test full scale jacket node geometries with different weld methods on their fatigue performance typically 20 times faster allowing a rapid interpretation of the results.

Project start and end dates

Jan 2017 - Dec 2023

Project lead

OCAS

Partners
  • Innovator: OCAS Technology
  • Funders: Ørsted, Equinor, SPR, Vattenfall, EnBW, SGRE, SSE, Shell + Public support from the Scottish Government
  • In kind contributions: BiFab, Heerema, Kvaerner, EEW, Navantia, Dillinger, Salzgitter, ArcelorMittal
  • ITRP: DNV-GL, Bureau Veritas, BAM
Contact
James Sinfield

James Sinfield, Technology Acceleration Manager
james.sinfield@carbontrust.com