Mock-up of a support structure of the ITER vacuum vessel

The ITER vacuum vessel support systems located in the lower level sustain loads in radial and vertical direction. The support system consists of various sub-components like a linkage system, a pot type bearing, a vertical rope, a toroidal constraint, and dampers. In order to examine performance of the mechanism of the system, a mock-up of the linkage system which is comparatively complicated has been manufactured. Various fabrication methods were studied through the mock-up fabrication, and also several tests have been done using the mock-up. Those include assembly study, stroke test, static load test and fatigue test. In the full stroke test, the functional mechanism of the support structure has been demonstrated. In the structural test, the strength of the all components is evaluated by measuring reaction and strain of each component. In order to investigate the effect of tolerances and the damage due to the tests, the performance tests were conducted before and after the static and fatigue tests. The backlash for each stage is found from measured displacement hysteresis. As results of those tests, the performance of the ITER vacuum vessel support structure as well as its structural integrity has been evaluated in this study.