Thermo-mechanical analysis of DTT Vacuum Vessel Thermal Shield

The Thermo-structural behavior of the Vacuum Vessel (VV) and Vacuum Vessel Thermal Shield (VVTHS) of the Divertor Tokamak Test (DTT) project under thermal loads and piping-induced stresses was evaluated using Finite Element Analysis (FEA). The THS consists of two shells, respectively referred as inner THS and outer THS, with Cooling Pipes (CPs) welded to the innermost. The VV and THS are mechanically coupled by using bolts that constrain relative displacements. A Finite Element Model (FEM) was developed using shell elements for VV and VVTHS, beam elements for CPs and bolts, and coupling equations to simulate bolted connections. The analysis incorporated temperature-dependent material properties and periodic cycling conditions for applied on VV. Results provide insight into the displacement and stress distributions across the components, informing the structural integrity and future design optimization of the DTT VVTHS system.