Abstract
A commonly used material in offshore structures is S355 structural steel. For example, during the monopile fabrication process, the material is pre-strained to different levels at different depths through the thickness. Therefore, the influence of pre-straining on fatigue life and crack growth behaviour of the material needs to be examined and considered for design and life assessment procedures. In the present study, uniaxial fatigue and fatigue crack growth tests have been conducted on materials with different pre-strain levels and the results are compared with the un-strained material state. From the test data, it has been seen that the S-N fatigue life will reduce with increasing pre-straining level, while the fatigue crack propagation rate remains largely unchanged in pre-strained material. The results from this study are compared with the recommended S-N fatigue and fatigue crack growth trends available in standards and are discussed in terms of the applicability and level of conservatism in the recommended curves to account for the material pre-straining effects on the fatigue life assessment of offshore structures.
| Original language | English |
|---|---|
| Article number | 106707 |
| Journal | Journal of Constructional Steel Research |
| Volume | 183 |
| Early online date | 25 Apr 2021 |
| DOIs | |
| Publication status | Published - 31 Aug 2021 |
Funding
This work was supported by grant EP/L016303/1 for Cranfield, Oxford and Strathclyde Universities, Centre for Doctoral Training in Renewable Energy Marine Structures - REMS ( http://www.rems-cdt.ac.uk/ ) from the UK Engineering and Physical Sciences Research Council (EPSRC) .
Keywords
- fatigue
- material pre-straining
- monopile
- offshore wind
- S-N curve
- S355