Aiming at understanding thermo-mechanical loads in the first wall of DEMO: Stress-strain evolution in a Eurofer-tungsten test component featuring a functionally graded interlayer

摘要

For the future fusion demonstration power plant, DEMO, several blanket designs are currently under consideration. Despite geometric and operational differences, all designs suggest a first wall (FW), in which tungsten (W) armour is joined to a structure made of Reduced Activation Ferritic Martensitic (RAFM) steel. In thermomechanical analyses of breeding blankets, this joint has received limited attention. In order to provide a basis for better understanding of thermally induced stresses and strains in the FW, the thermo-mechanical behaviour of a water-cooled test component is explored in the current contribution. The model aims at providing a simple geometry that allows straightforward comparison of numerical and experimental results, while trying to keep boundary conditions as realistic as possible. A test component with direct RAFM steel-W joint, and a test component with a stress-redistributing, functionally graded RAFM steel/W interlayer in the joint is considered in the current contribution. The analyses take production- and operation-related loads into account. Following a detailed analysis of the evolution of stress components and strain in the model, a parameter study with respect to geometric specifications and loads is presented.