Determination of Loading and Residual Stresses on Offshore Jacket Structures by X-ray Diffraction

As basements of offshore wind turbines (OWTs) in deep water (>50 m), jacket structures are an economic alternative to monopiles. For this reason, the structural durability jackets has become more important. In such structures, welded tubular joints weak points for fatigue design. The harmful effect tensile residual stresses welding is well known. these reasons, and loading were determined by X-ray diffraction (XRD) using a mobile diffractometer. This allows us directly determine load stress at fatigue-critical locations, namely weld toe testing rig. High up 250 MPa (and unloaded) condition. At loaded structure (10,000 cycles), lower level was determined. During loading, local increase joint that between 1.4 4 times higher than applied nominal Furthermore, it shown additional treatment (grinding clean blasting) influences state significantly.