The European Pressure Vessel Standard EN 13445 provides in its part 3 (Design) a simplified method (Clause 17) and a detailed method for fatigue assessment (Clause 18). Clause 18 “Detailed Assessment of Fatigue Life” is under revision within the framework of the European working group CEN/TC 54/WG 53 - Design methods to reach a significant increase in user-friendliness and a clear guideline for the application.
This paper is focused on the new informative annex NA “Instructions for structural stress oriented finite elements analyses using brick and shell elements”. As an essential amendment for the practical user the determination of structural stress ranges for fatigue assessment of welds is further specified in this new annex. Different application methods for the determination of structural stresses are explained in connection with the requirements for finite element models and analyses.
This paper will give an overview of the proposed approaches of structural stress determination in annex NA of the revised EN 13445-3. It will present the results of fatigue analyses according to EN 13445-3 Clause 18 from a round robin test with participants of the German working group for different application examples. The estimated structural stress ranges for the proposed approaches of structural stress determination will be compared. This comparison leads to general remarks and open points for the different approaches.
Furthermore it is concludes that further comparisons, e.g. with results of other pressure vessel design codes are desirable.