DNV DNVGL-RP-C203 PDF

This recommended practice gives methods for fatigue analyses based on S-N data from testing for the following steel structures and components:

— Fixed and floating steel structures used for exploitation and for production of oil and gas

— Risers and pipelines

— Support structures for wind turbines

— Different types of welded connections

— Cast and forged joints

— Bolted connections

— Connectors

— Small diameter umbilicals made of super duplex steel.

The document specifies and gives guidelines for:

— S-N data in air environment, seawater with cathodic protection and seawater with free corrosion

— stress concentration factors for some details where these can be derived from analytical considerations or from detailed finite element analysis

— simplified fatigue design based on allowable stress ranges for various S-N data and Weibull long-term stress distributions

— the use of various design methods based on nominal stress, hot spot stress or notch stress

— post weld improvement such as grinding, TIG dressing and hammer peening.