APPLICAZIONE ACCELERATA DEL PEAK STRESS METHOD PER L’ANALISI AGLI ELEMENTI FINITI DI STRUTTURE SALDATE SOLLECITATE A FATICA: DEFINIZIONE E VALIDAZIONE DI REGOLE PER L’INFITTIMENTO LOCALE DELLA MESH

Local approaches for fatigue assessment of welded joints based on notch stress intensity factors (NSIFs) assume the weld root and the weld toe as sharp-V notches. The Peak Stress Method (PSM) is a local approach able to rapidly estimate the NSIFs starting from the linear elastic peak stresses calculated from a finite element analysis where a rather coarse mesh pattern has been adopted, the element size being uniform in the entire model. In the context of the fatigue design of large-scale welded structures, extending a uniform mesh to the entire model can lead to prohibitive solution and post-processing times, even if the average element size prescribed by the PSM is coarse, when compared to that required to evaluate NSIFs starting from local stress distributions. Therefore, the aim of the present work is to verify the possibility of limiting the element size prescribed by the PSM to the region of the notch tip, by defining (i) its extension and (ii) the maximum element size that can be adopted outside.