Suifficent choice of material to avoid brittle fractures of foundation components of offshore wind power plants made of steel in accordance with EC3 part 1‐10

The choice of material for steel constructions in maritime environments, e.g. wind power plants, is not included in EC3 yet. On the other hand rules for a suifficent choice of material for structures in maritime environments do not exist. Till now, no physically based design method for the choice of steel grade in such environments exist. But a suitable and demand oriented choice of steel grade is very important for an economic design. A failure due to brittle fracture is avoided by a suitable choice of steel grade or rather by limitation of the maximum plate thickness. A physically based design method is given in EC3 part 1–10. Here table 2.1 shows the values of the maximum plate thickness in dependence of the steel grade and reference temperature. All data in table 2.1 were determined on the basis of assumptions with a clear focus on bridge constructions. Therefore, it is doubtful if table 2.1 can also be used for offshore wind power plants. For example crack growth parameters (constants in Paris‐law) have an influence on the brittle fracture design which are different for regular conditions of bridges in comparison to maritime environments. A research project was carried out at the University of applied sciences Mittelhessen (THM). As a first step it was investigated which individual boundary conditions differ between bridge construction and foundations in maritime environments. In the second step tabulated values of the maximum plate thickness with the adapted boundary conditions were determined based on the same calculation algorithm as EC3 part 1‐10. Finally a recommendation for the practice‐oriented use of Table 2.1 was developed for foundation components of offshore wind power plants.