Analysis of welding deformation on CFETR 1/32 vacuum vessel mockup

Highlights: • Welding deformation simulation of 1/32 VV was completed based on inherent strain theory. • Welding jigs and fixtures were used to reduce the welding deformation of 1/32 VV. • Reserved allowance could effectively compensate the welding shrinkage of 1/32 VV. • Measuring the on-site welding deformation of 1/32 VV by laser tracker. -- Abstract: The sub-sector of China Fusion Engineering Test Reactor (CFETR) vacuum vessel is fully welded together with four poloidal segments which will produce larger welding deformation in the progress of welding. So it is necessary to adopt some methods to control the welding deformation. In this paper, the simulation of welding deformation on 1/32 vacuum vessel mockup was performed by using finite element method. And the methods of welding fixtures and reserved allowance for welding shrinkage were adopted to reduce the welding deformation. Finally, through measuring the on-site welding deformation by laser tracker, the welding deformation direction and size of 1/32 vacuum vessel were obtained, which will accumulate experience for the formal construction of CFETR vacuum vessel.