1. Update on ARIES-CS Coil Structural Analysis X.R. Wang and A.R. Raffray ARIES Meeting PPPL, NJ October 4-5, 2006

2. What is new?  The coil structure material has been updated to JK2LB.  2 maintenance ports have been included the latest 3D solid modelling in order to analysis the local impacts on the openings in the coil supporting tube.

3. Max. Von Mises stress of the coil structure without openings Max. Von Mises Stress: 652 MPa Max. Disp: ~2.0 cm 35 cm coil structure 30 cm strong-back

4. Finite element model including two openings  The magnetic force loads are the same as before.  The boundary conditions maintain the same: Winding packs are fully bonded to the grooves in the coil tube; Cyclic symmetry boundary are applied at the both ends of the coil supporting tube. Cyclic symmetry boundary Cyclic symmetry boundary Openings for maintenance ports: 2.2 m (toroidal) x 4.4 m (poloidal)

5. Material Properties for the Coil Supporting Structure* The design stress is taken as 2/3 of the yield strength at 4 K. MaterialIncoloy 908 (4K)JK2LB(4K) Yield strength1227 MPa1420 MPa Tensile strength1892 MPa1690 MPa Modulus of elasticity 1.823 x 10 11 MPa~2.0 x 10 11 MPa * Elongation28.5% Poisson’s ratio0.3030.3* Design stress818 MPa946 MPa * Recomondded by H. Nakajima, ITER Superconducting Magnet Technology Group, Japan Atomic Energy Agency (JAEA).

6. Max. Displacement of the Coil Structure  The results indicate the maximum displacement of 2.10 cm at the outboard of the coil supporting tube.  Contour shows a good symmetry because of the symmetric structure and EM loadings. Max. Displacement: 2.1 cm

7. Max. Von Mises Stress of the Coil Structure Max. Von Mises Stress: 656 MPa The Max. Von Mises stress of 656 MPa is found at inboard side of the coil supporting tube. The Max. stress occurs locally at very small region only. Most regions of the coil supporting tube including the inter-coil structure shell and strong- back are in a low stress level.

8. Comparison of the displacement contours between the two coil supporting tube (With 2 openings at the ends, Max. Displacement ~2.1 cm) (Without any openings, Max. Displacement ~2.0 cm )

9. Summary  The structural analysis results of the coil supporting tube with two major maintenance port openings show a small difference, ~5% in the maximum displacement and 1% in the maximum stress.  Maintenance port openings in the coil structure are not a major concern because the ports are in low stress regions.