Corrosion Fatigue Crack Growth in Offshore Wind Monopile Steel HAZ Material

Abstract

Offshore wind is an emerging clean and environmentally friendly renewable energy source that has developed rapidly to meet the European Union 2020 renewable energy targets. Monopiles are the most commonly used offshore wind turbine support structures and are exposed to harsh marine environments similar to those experienced by structures for oil and gas applications. However, they have significantly different design requirements due to operational loads envelope and structural stiffness. Therefore the knowledge of corrosion assisted fatigue damage in monopile support structures is of a vital importance to ensure economical and safe operation of the structures in service. In this paper, results are presented on fatigue crack growth of HAZ (Heat Affected Zone) specimens made of S355 J2+N steel in air and in free corrosion conditions. The fatigue crack response in the HAZ materials are compared tothat of the base material and significant difference in the test results is discussed