Crack propagation analysis of ITER Vacuum Vessel port stub with Radial Basis Functions mesh morphing

The ITER Vacuum Vessel (VV) is one of the most important components of the tokamak machine. The severe operating conditions impose a design to withstand strong dynamic loads. A special focus is put on defects embedded in the component that, due to the not total accessibility of the VV to non-destructive examination (NDE), but also to identify their minimum safe dimension, must be assessed through Fracture Mechanics (FM) analyses. Nuclear codes give useful guidelines for design verification using simplified models that, for practical sake, do not give a detailed description of the physical phenomena. Nowadays, Finite Element Method (FEM) is a common tool for the assessment of structural components, and detailed methods for Crack Propagation analyses have been developed. A novel procedure for the crack shape evolution during cyclic loadings will be presented in this article, relying on Finite Elements Analysis (FEA) in conjunction with Radial Basis Function morphing technique, allowing a fast arrangement of the existing mesh to a new configuration. The results of the proposed method are compared with those available in literature references and in nuclear codes