Efficient computation of the strain energy density for the assessment of fracture and fatigue of welded structures

Nowadays, the most widespread approach to fatigue design is based on S-N curves. Although this approach works in a lot of practical situations, there are also many others in which it does not give enough accurate results: The most important exception are probably the welded joints, which are widely adopted for the connection of\nstructural parts.\n\nIn recent years, many authors suggested to assess the fatigue life of welds on the basis of the local stress and strain fields in the most stressed zones, using the concepts of fracture mechanics. It was in this context that the SED criterion was formulated.\n\nThe purpose of this work is to investigate the numerical implementation of the SED criterion, and to further enhance its efficiency on the basis of some theoretical observations, as we are going to explain in details.