Numerical Fatigue Strength curve for the C1 Wedge Connection

This paper presents an investigation on the fatigue life prediction of the C1 Wedge Connection based on advanced finite element analysis. Recently developed, this connection links tubular sections of wind turbine towers using small horizontally placed bolts to slide two wedges, which pull the fork‐shaped upper flange and shaft‐shaped lower flange of the tower together. The fork‐shaped upper flange is manufactured using electron beam welding. A 3D finite element model is developed in ABAQUS software to simulate the behavior of the connection. A sequential thermal‐mechanical analysis is performed to simulate the electron beam welding process and estimate the residual stresses and distortions. The crack initiation at the lower flange, where the largest stress range is observed, governs the fatigue resistance of the connection. Fatigue crack initiation is assessed using the strain‐based local approach and code‐based methods such as the EN1993:1‐9 and DNV‐RP C2003. A comparison of the predictions from these methods is presented.