Life Cycle Tests
To evaluate and qualify friction interfaces for demanding fusion environments, service life tests were conducted under highly representative conditions. Test setups were developed for multi-axial loading with normal forces up to 1.5 MN and friction forces up to 200 kN. The tests were performed under cryogenic temperatures down to 77 K, vacuum conditions of 1E-6 mbar, and elevated temperatures up to 200 °C.
Various material combinations, surface geometries, and coating systems were examined under realistic boundary conditions, enabling long-term performance assessment through life cycle tests with several thousand load cycles.
Various material combinations, surface geometries, and coating systems were examined under realistic boundary conditions, enabling long-term performance assessment through life cycle tests with several thousand load cycles.
Multidiciplinary Analyses and Experimental Thermal Invenstigation
A detailed simulation and verification project was conducted to assess the structural and thermal loads on a bolometer camera used in fusion experiments. Electromagnetic loads due to plasma disruptions were analyzed using a custom-developed simulation routine, incorporating time-varying magnetic fields from DINA simulations to calculate eddy currents, resulting magnetic forces, and their effects on structural integrity, including stresses and bolt loads. Optimization measures included the evaluation of insulation layers and alternative materials to reduce eddy currents and thermal deformation.
Thermal analysis addressed complex load conditions, including radiation from plasma and divertor modules, heat conduction from the vacuum vessel, and nuclear heating. Temperature-dependent material properties and their impact on thermal displacements and mechanical stresses were investigated, including effects on screw pretension caused by differing coefficients of thermal expansion.
FE analyses highlighted the critical role of thermal contact conductivity between components and the vessel wall. A dedicated experiment was carried out using a full-scale bolometer camera to verify thermal interface properties. The strong correlation between experimental and simulation results validated the model, enabling confident application of the FE model to future thermal load cases and supporting design improvements for durability and performance.
Thermal analysis addressed complex load conditions, including radiation from plasma and divertor modules, heat conduction from the vacuum vessel, and nuclear heating. Temperature-dependent material properties and their impact on thermal displacements and mechanical stresses were investigated, including effects on screw pretension caused by differing coefficients of thermal expansion.
FE analyses highlighted the critical role of thermal contact conductivity between components and the vessel wall. A dedicated experiment was carried out using a full-scale bolometer camera to verify thermal interface properties. The strong correlation between experimental and simulation results validated the model, enabling confident application of the FE model to future thermal load cases and supporting design improvements for durability and performance.
