SIMULATION OF ELECTROMECHANICAL AND THERMOMECHANICAL LOADS ON FIRST WALL MOCK-UPS

In order to study the boundary conditions for the occurrence of ratche ting, a testing rig was erected. In this rig, small-scale mock-ups of the first wall were tested under mechanical conditions similar to thos e expected during disruptions. These mock-ups were made of stainless s teel AISI 316. They were heated on the surface and water cooled from i nside. Disruption forces were simulated by a high-speed hydraulic bend ing system by impact loads. The mock-ups were heated by a high-frequen cy generator and cooled by water through two cooling channels. In addi tion to the experimental work, simplified analytical analysis and nume rical calculations were carried out using the finite element program A BAQUS. In these calculations, the temperature and stress fields in the mock-ups were investigated and the influence of the different constit utive equations was studied. The experimental results confirm the ratc heting behaviour predicted by the calculations. It has been demonstrat ed that the ratcheting behaviour for constant mechanical and cyclic th ermal loads is much stronger than in the case when both loads are cycl ic in nature.