Stress simulation on a round wheel W target S. Jin 1 , P. Sievers 2 - PowerPoint PPT Presentation

Stress simulation on a round wheel W target S. Jin 1 , P. Sievers 2 , T. Omori 3 , J.Gao 1 1 IHEP; 2 CERN; 3 KEK; POSIPOL2017, BINP, Novosibirsk, Russia, Sept. 18-21, 2017 . 1

Outline • Introduction • Simulation results of full ring and sliced ring • Summary 2

Introduction • Main structure of the model Tungsten for power deposition  For model 1, there is no slots in tungsten part;  For model 2, the tungsten is sliced to 10 parts by the slot with a width of 0.2mm; Tungsten  An intermetallic contact between the W and the Cu, like brazing, is assumed, with a Cooling water thermal conductance of 2 W/(cm^2 ▪ K) Cooper  The average power is deposited uniformly in time and space over the top part of the W. In total about 35 Kw  The water temperature is 50K. 3

Model-1 4

Model-1 • Boundaries: No slot for • Water Temperature: 50C tungsten • Thermal Conductance for both of water-Cu and W –Cu surface: 0.02W/mm^2 • Power is only deposited in the top part of the W with 0.0795W/mm^3 • There is a Cu bar with diameter of 30mm in the center. We fixed it. 5

Results: Temperature distribution 6

interface Temperature path 10mm There will be a temperature jump at the interface. 7

Temperature path The temperature is obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 8

Results: v. M. Stresses 9

v. M. stresses interface 100 95 v. M.stress (MPa) 90 path 85 v.M.stress (Mpa) 10mm 80 75 70 65 60 0 5 10 15 20 25 30 35 l(mm) 10

The v. M. stresses 140 Interface v.M.Stress at W 130 Interface v.M.Stress at Cu 120 110 path v. M.stress(MPa) 100 90 80 70 60 50 40 0 5 10 15 20 l(mm) The v. M. stresses are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 11

Sigma r 150 Interface sigma r(y) at W 130 Interface sigma r(y) at Cu 110 Stress at radial direction(MPa) 90 path 70 50 30 10 -10 -30 -50 0 5 10 15 20 l(mm) The stresses at radial direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 12

Sigma phi 200 Interface sigma phi(x) at W 150 Interface sigma phi(x) at Cu Stress at phi direction (MPa) 100 path 50 0 -50 -100 -150 0 5 10 15 20 l(mm) The stresses at phi direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 13

Sigma z 15 Interface sigma z at W 10 Interface sigma z at Cu Stress at axial direction (MPa) 5 path 0 -5 -10 -15 -20 0 5 10 15 20 l(mm) The stresses at axial direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 14

Stresses at the other side of Cu. Stresses for Cu at interface. The Stress here should be because the center bar is fixed as a boundary condition. 15

Model-2: Sliced W-target with 10 gaps of 0.2mm 16

Model-2: sliced W-target with 10 gaps of 0.2mm The gap is 0.2mm 17

Results: Temperature distribution They are essentially the same as in the full ring, as expected. 18

Results: Stresses 19

v. M. Stresses distribution at interface v. M. stress in-plane of contact surface at W wheel v. M. stress in-plane of contact surface at Cu wheel 20

Stresses at center of the sector 21

The v. M. stresses path  The v. M. stresses are obtained at the surfaces which are both 0.1mm off the interface for Cu and W.  There a binning problem. It should not be a real data. 22

Sigma r path The stresses at radial direction (sigma x) are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 23

Sigma phi path The stresses at phi direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 24

Sigma z path The stresses at axial direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 25

Stresses at end of the sector 0.2mm gap Path for W is on the surface of W due to gaps 26

The v. M. stresses path Point which has max. stress  The v. M. stresses are obtained at the surfaces which are both 0.1mm off the interface for Cu and W.  Path for W is on the surface of W due to the gaps.  Discussion: the max. stress in this picture appearing at the point shown in the picture is about 164Mpa. However, the max. stress for whole model is about 208MPa. It appears at the similar point in one of k connection positions between gaps and Cu cooler.

Sigma r path The stresses at radial direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 28

Sigma phi path The stresses at phi direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 29

Sigma z path The stresses at axial direction are obtained at the surfaces which are both 0.1mm off the interface for Cu and W. 30

Stresses check near the interface at end of the sector • Model: it is the same as model-2 • The v. M. stresses at end-surface are calculation near the interface at end of sector Path at interface: Path(x,y,z /mm)= (-0.1, 220, -20) to (-0.1, 240, -20) Z: to the inside of paper 31

So, we check the paths as following: W: W: (-0.2, 220, -20.1) to (-0.2, 240, -20.1) (-1.0, 220, -20.2) to (-1.0, 240, -20.2) (-0.4, 220, -20.1) to (-0.4, 240, -20.1) (-1.0, 220, -20.4) to (-1.0, 240, -20.4) (-0.6, 220, -20.1) to (-0.6, 240, -20.1) (-1.0, 220, -20.6) to (-1.0, 240, -20.6) (-0.8, 220, -20.1) to (-0.8, 240, -20.1) (-1.0, 220, -20.8) to (-1.0, 240, -20.8) (-1.0, 220, -20.1) to (-1.0, 240, -20.1) (-1.0, 220, -21) to (-1.0, 240, -21) Cu Cu (-0.2, 220, - 19.9) to (-0.2, 240, - 19.9) (-1.0, 220, - 19.8) to (-1.0, 240, - 19.8) (-0.4, 220, - 19.9) to (-0.4, 240, - 19.9) (-1.0, 220, - 19.6) to (-1.0, 240, - 19.6) (-0.6, 220, - 19.9) to (-0.6, 240, - 19.9) (-1.0, 220, - 19.4) to (-1.0, 240, - 19.4) (-0.8, 220, - 19.9) to (-0.8, 240, - 19.9) (-1.0, 220, - 19.2) to (-1.0, 240, - 19.2) (-1.0, 220, - 19.9) to (-1.0, 240, - 19.9) (-1.0, 220, - 18) to (-1.0, 240, - 18) Path at Path at interface interface : : 32

v. M. stress for W 180 W: x=-0.1 (W) (-0.2, 220, -20.1) to (-0.2, 240, -20.1) x=-0.2 (W) 160 (-0.4, 220, -20.1) to (-0.4, 240, -20.1) x=-0.4 (W) (-0.6, 220, -20.1) to (-0.6, 240, -20.1) 140 x=-0.6 (W) (-0.8, 220, -20.1) to (-0.8, 240, -20.1) x=-0.8 (W) (-1.0, 220, -20.1) to (-01.0, 240, -20.1) 120 x=-0.10 (W) v.M.stress (MPa) Along the interface at tungsten 100 80 Path at interface 60 : 40 20 0 0 5 10 15 20 l(mm) 33

v. M. stress for Cu 140 Cu x=-0.1 (Cu) (-0.2, 220, - 19.9) to (-0.2, 240, - 19.9) x=-0.2 (Cu) (-0.4, 220, - 19.9) to (-0.4, 240, - 19.9) 130 x=-0.4 (Cu) (-0.6, 220, - 19.9) to (-0.6, 240, - 19.9) x=-0.6 (Cu) (-0.8, 220, - 20.1) to (-0.8, 240, - 19.9) x=-0.8 (Cu) 120 (-1.0, 220, - 19.9) to (-1.0, 240, - 19.9) x=-0.10 (Cu) v.M.stress (MPa) Along the interface at Cu 110 Path at interface 100 : 90 80 0 5 10 15 20 l(mm) 34

v. M. stress for W 160 z=-20.2 (W) 140 W: z=-20.4 (W) (-1.0, 220, -20.2) to (-1.0, 240, -20.2) z=-20.6 (W) 120 (-1.0, 220, -20.4) to (-1.0, 240, -20.4) z=-20.8 (W) (-1.0, 220, -20.6) to (-1.0, 240, -20.6) z=-21 (W) (-1.0, 220, -20.8) to (-1.0, 240, -20.8) 100 v.M.stress (MPa) (-1.0, 220, -21) to (-1.0, 240, -21) 80 The path at interface is 1mm far 60 from end section. Path at interface: 40 20 0 0 5 10 15 20 l(mm) 35

v. M. stress for Cu 130 125 Cu (-1.0, 220, - 19.8) to (-0.2, 240, - 19.8) 120 (-1.0, 220, - 19.6) to (-0.4, 240, - 19.6) 115 (-1.0, 220, - 19.4) to (-0.6, 240, - 19.4) (-1.0, 220, - 19.2) to (-0.8, 240, - 19.2) v.M.stress (MPa) 110 (-1.0, 220, - 18) to (-1.0, 240, - 18) 105 z=-19.8 (Cu) z=-19.6 (Cu) Path at interface: 100 z=-19.4 (Cu) 95 z=-19.2 (Cu) 90 z=-19.0 (Cu) 85 80 0 5 10 15 20 36 l(mm)

Comparison and Conclusion Peak Peak v.M Stresses at interface (Mpa) tempature( ℃ ) stress (MPa) v.M.stress sigma r sigma phi sigma z 40 to 130 20 to 120 -50 to 150 -15 to 10 interface for W 377 at W 251 at W 65 to 125 -30 to 10 -140 to -50 -12 to 0 Full ring interface for Cu 40 to 100 20 to 80 40 to 100 -3 to 7 interface near center of section for W 208 at 80 to 135 -10 to 25 -130 to -50 -2 to 13 interface near center of section for Cu 380 at W Sliced ring interface 20 to 150 -90 to 10 -30 to 15 -45 to -4 interface near end surface of section for W 90 to 130 -90 to -30 -140 to -100 -5 to 1 interface near end surface of section for Cu  Sliced ring suffer much less stress.  However, we need to pay attention to the interface. This can lead to fatigue and thus to loss Sliced ring Full ring of thermal contact. 37

Thanks ！ 38