ITER TF coil double pancake assembly: Laser welding numerical simulation

In the frame of the ITER coils production, one crucial point is the cover plate welding to complete a coil layer, the so called double pancake (DP). The scope of the activity here described is the assessment of the deformation induced by this laser welding through a FE numerical simulation, in order to find the welding sequence that minimize the global distortion. At this concern, the Local–Global approach technique has been adopted using Abaqus Code, in order to be able to compare several long welding paths in acceptable CPU time increasing analysis speed and model definition easiness in spite of partial loss in the results accuracy. The numerical methodology has been tuned and assessed on experimental data from a welding sample in which a 2.5 mm deep welding has been performed and the deformation induced by 1 and 2 mm deep welds (the ones that will be used in the complete DP) has been extrapolated. These local strains have then been applied on the global models reproducing the middle and side DP, and their deformation has been computed. ther good fitting between the experimental and numerical results is very promising, and a complete asses of the procedure could be performed in the frame of an experimental–numerical research campaign.