Joint Institute for Nuclear Research Deformations and stresses in the flux return yoke A.Efremov, Yu.Lobanov, A.Makarov Darmstadt,

2 Yoke and support front view

3 Yoke cross-section

4 FE model (1) Optimization purpose: minimization of the deformation difference between different cases of support point positions (wheels, lifts and permanent supports) minimization of deformation of the platform supporting the doors Door gravity load points (when the doors are attached to the barrel) The door halves are fixed to each other Cryostat and detectors weight application points (2 options) Iron yoke (distributed gravity load) The yoke weight is supported by the vertical frames

5 FE model (2) Door gravity load points (when the doors are attached to the barrel) The door halves are fixed to each other Optimization purpose: minimization of the deformation difference between different cases of support point positions (wheels, lifts and permanent supports) minimization of deformation of the platform supporting the doors Cryostat and detectors weight application points (2 options) Iron yoke (distributed gravity load) The yoke weight is supported by the vertical frames

6 Deformations due to gravity: 3 points of support  H = -0.1 mm  X 1 = +0.6 mm  X 2 = -0.4 mm The doors are staying on the rails supported by the jacks  y = -0.4 mm H X1X1 X2X2 Support point Cryostat and detectors are supported by the lower barrel beam  y max = -0.9 mm

7 Deformations due to gravity: 2 points of support  H = +1.0 mm  X 1 = -0.3 mm  X 2 = -1.7 mm The doors are supported by the side barrel beams  y = -1.7 mm H X1X1 X2X2 Support point Cryostat and detectors are supported by the lower barrel beam  y max = -1.7 mm

8 Deformations due to gravity: 3 points of support  H = -1.2 mm  X 1 = +1.9 mm  X 2 = +0.4 mm The doors are staying on the rails supported by the jacks  y = -0.1 mm H X1X1 X2X2 Support point Cryostat and detectors are mounted at the upper barrel beam  y max = -1.6 mm

9 Deformations due to gravity: 2 points of support  H = -1.0 mm  X 1 = +1.7 mm  X 2 = +0.3 mm The doors are supported by the side barrel beams  y = -0.3 mm H X1X1 X2X2 Support point Cryostat and detectors are mounted at the upper barrel beam  y max = -1.7 mm

10 Stresses due to gravity: 2 points of support The doors are supported by the side barrel beams Support point Cryostat and detectors are supported by the lower barrel beam

11 Stresses due to gravity: 3 points of support The doors are staying on the rails supported by the jacks Support point Cryostat and detectors are supported by the lower barrel beam

12 Deformations due to gravity and seismic loads ( 3 points of support)  H = mm  X 1 = mm  X 2 = mm The doors are attached to the barrel Cryostat and detectors are supported by the lower barrel beam  x max = 2 mm a X = 1.5 m/s 2

13 Deformations due to gravity: 2 points of support  H = +0.7 mm  X 1 = -0.1 mm  X 2 = -1.3 mm The doors are supported by the side barrel beams H  y = -1.5 mm X1X1 X2X2 Support point Cryostat and detectors are supported by the lower barrel beam  y max = -1.5 mm

14 Deformations due to gravity: 3 points of support  H = -0.2 mm  X 1 = +0.6 mm  X 2 = -0.2 mm The doors are staying on the rails supported by the jacks Cryostat and detectors are supported by the lower barrel beam  y max = -0.9 mm H X1X1 X2X2 Support point

15 Stresses due to gravity: 2 points of support The doors are supported by the side barrel beams Support point Cryostat and detectors are supported by the lower barrel beam

16 Stresses due to gravity: 3 points of support The doors are staying on the rails supported by the jacks Support point Cryostat and detectors are supported by the lower barrel beam

17 Comparison of deformations (in mm) Magnet support option Application of cryostat and detectors weight The doors are fixed to the barrel The doors are staying on the supports HH X1X1 X2X2 HH X1X1 X2X2 2 supports Lower beam Upper beam supports Lower beam Upper beam Magnet support option Application of cryostat and detectors weight The doors are fixed to the barrel The doors are staying on the supports HH X1X1 X2X2 HH X1X1 X2X2 2 supports Lower beam Upper beam supports Lower beam Upper beam The lower frame with nominal cross section The lower frame with increased cross section

18 Deformations due to gravity: 4 points of support  H = -0.4 mm  X 1 = +0.8 mm  X 2 = 0.04 mm The doors are staying on the rails supported by the jacks Cryostat and detectors are supported by the lower barrel beam  y max = -1.1 mm H X1X1 X2X2 Support point

19 Summary The deformations of the yoke in the framework of the considered concept of the movable platform (4 pairs of the railing wheels) are reduced to about 1 mm. Increasing the thickness of the platform beam does not significantly reduce the relative deformation of the yoke, while leads to more complicated (and expensive) design The suspension system for cryostat and detectors should be designed so that their positions would not critically depend on the yoke deformations (their weight should be mainly transferred to the lower beam of the yoke barrel, etc) In order to ensure the rails supporting the doors to be straight-line (for the unhindered door sliding), the supports for them in the experimental hall should be provided (in addition to the jacks supporting the main platform) Further possible solutions of increasing the yoke stiffness (increasing the thickness of vertical support frames or upper horizontal frame; welding of units) will be analyzed The comprehensive analysis of deformations in the complete 3D FE model of the yoke will be performed; we need information on external (magnetic) forces as input data