IIW Fatigue Assessment Procedures

Numerous fatigue assessment methods have been introduced to assess the durability of metal structures under dynamic loading. Finite element (FE) modeling is an integral part of most design and analysis work, and methods have evolved as the analysis possibilities have become more sophisticated and computers have increased in speed and memory capacity. Fatigue assessment places two conflicting demands on the analysts. The fatigue damage process itself is highly local, thus requiring a fine FE mesh. On the other hand, welded structures are frequently large and geometrically complex, they have numerous load input locations, and they have boundary conditions which may be difficult to define. These demands are best satisfied with a large FE model. Because of this conflict, fatigue assessment is frequently the slowest link in the design process of welded structures.