Influence of artificial seawater corrosion on the fatigue strength of 40 mm thick welded details for offshore wind support structures

Offshore wind support structures are exposed to cyclic loading and harsh environmental conditions that can promote corrosion and potentially affect fatigue performance. This study investigates the influence of long-term artificial seawater corrosion on the fatigue strength of thick welded steel details representative of offshore applications. Butt-welded and fillet-welded joints with plate thickness of 40 mm were exposed to artificial seawater for 12 months and subsequently tested under four-point bending fatigue loading. Changes in weld geometry induced by corrosion were quantified using optical 3D surface scans. The results show that artificial seawater does not reduce the characteristic fatigue strength of the investigated joints. While butt welds exhibit comparable fatigue performance before and after corrosion, fillet welds show an increase in fatigue strength due to corrosion-induced smoothing of the weld toe geometry. These findings indicate that corrosion-induced surface modifications should be considered in fatigue assessment and lifetime extension strategies for offshore wind support structures.

Subjects

Offshore wind support structures

fatigue strength

welded joints

artificial seawater corrosion

3D surface scanning; weld geometry

lifetime extension

DDC Class

623: Military Engineering and Marine Engineering

620.1: Engineering Mechanics and Materials Science

Lizenz

https://creativecommons.org/licenses/by/4.0/

Publication version

publishedVersion

Name

v003t03a008-omae2026-182297.pdf

Type

Main Article

Size

2.62 MB

Format

Adobe PDF

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Influence of artificial seawater corrosion on the fatigue strength of 40 mm thick welded details for offshore wind support structures