1 / 25

RF-Structures Mock-Up FEA Assembly Tooling V. Soldatov , F. Rossi, R. Raatikainen 27.6.2011

RF-Structures Mock-Up FEA Assembly Tooling V. Soldatov , F. Rossi, R. Raatikainen 27.6.2011. INDEX. EBW tooling for PETS Introduction General description Assembly on tooling Transportation EBW process FEA Loading and Boundary Conditions Results Conclusions

fergal
Download Presentation

RF-Structures Mock-Up FEA Assembly Tooling V. Soldatov , F. Rossi, R. Raatikainen 27.6.2011

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RF-Structures Mock-Up FEA Assembly Tooling V. Soldatov, F. Rossi, R. Raatikainen 27.6.2011

  2. INDEX • EBW tooling for PETS • Introduction • General description • Assembly on tooling • Transportation • EBW process • FEA • Loading and Boundary Conditions • Results • Conclusions • Brazing tooling for AS • Introduction • General description • Assembly on tooling • Brazing process • FEA • Loading and Boundary Conditions • Results • Conclusions

  3. EBW tooling for PETS • Introduction • General description • Assembly on tooling • Transportation • EBW process • FEA • Loading and Boundary Conditions • Results • Conclusions • Brazing tooling for AS • Introduction • General description • Assembly on tooling • Brazing process • FEA • Loading and Boundary Conditions • Results • Conclusions

  4. General description Minitank assembly Closure assembly 2 Middle connection assy Minitank (short) assembly 271.5 mm EBW EBW Mock-up (damped) assembly NO 202 mm Frictional contact 614.35 mm Closure assy 1 Frictional contact EBW EBW

  5. Assembly on tooling • Bearing: allow EBW tooling rotation around its axis, once it is positioned on the EBW machine. • Upper cap cover: apply clamping force to PETS unit, once the nut is screwed on the threaded rod. • Upper bolt: fix upper cap cover and closure assy 2. • Eye-bolts: for lifting and handling. • Threaded rod (M16): connection between the upper and the lower cap cover. • Lower cap cover: sustain PETS unit during the assembly on the tooling. • Lower bolt: fix lower cap cover and closure assy 1. • Nut (M16): after it is screwed using a torque spanner, a compressive axial load is applied to PETS units (while the rod has tensile stresses). • Holding device: fix axial and angular position between minitanks and adapter disks. Nut Upper eye-bolt Bearing Upper bolt Upper cap cover Lateral eye-bolt Threaded rod Holding-device Lateral eye-bolt Lower bolt Lower cap cover Nut

  6. Assembly on tooling 1. The second mock-up (damped) assembly is inserted into the middle connection assy 2. Minitank assembly is positioned 3. Closure assy 1 is positioned 4. Threaded rod is inserted and the upper cap cover is positioned

  7. Assembly on tooling 6. Clamping force is applied using a torque spanner 7. Tack welding 5. The holding device is fixed 1st FEM analysis: calculate gap variation in function of the applied load

  8. Transportation 8. Rotation and transport to the EBW machine. EBW EBW 2nd FEM analysis: calculate the clamping force necessary to maintain the contact in the designed area (friction forces between adapter disks and mock-up bars are greater than mock-up bars weight) Frictional contact 9. The holding device is removed. Frictional contact EBW EBW

  9. Clamping force vs. Tightening torque TIGHTENING TORQUE (Ma) CLAMPING FORCE (Fv) Ma [Nmm] = Fv·(0.159·P + 0.578·d₂·µg + 0.5·dKm·µk) = ~ 3·Fv [N] • M16 • P = thread pitch (2 mm) • d2 = thread diameter (16 mm) • µg = friction coefficient of the thread (0.15) • dKm = average diameter of the bolt head (22.16 mm) • µk = friction coefficient of the bolt head (0.15) dkm

  10. EBW process Fixed V-support Welding Bearing Chuck driven by the welding machine Ground

  11. FEA Aim Calculate the axial force necessary to hold the assembly on the tooling during the EBW process Calculate the deformation involved in the process Hypothesis The problem is considered as a static structural and no dynamical effects were taken into account (e.g. rotational speed 0.004 rad/s) Model and initial clamping force range for further studies Maximum 50 kN Minimum 0.3 kN FE-model including: -All copper parts (Cu-OFE) of PETS -St.Steel PETS flanges, minitank and tooling Friction forces between adapter disks and mock-up bars are lower than mock-up bars weight (the contact is not in the designed area) The initial gap of 50 µm is reduced to zero. High deformations of minitanks occur.

  12. Loading & Boundary Conditions Clamping force • Bearing condition • The selected ball bearing allows ̴ 10 ̓(0.17°) of rotation • Rotation due to gravity is allowed • Translation d.o.f. is fixed 1st position 2nd position Gravity Fixed (Motor chuck) Gravity Fixed

  13. Results – Axial force of 1 kN Δgap max ̴1 µm Δdeflection ̴10.5 µm

  14. Results – Axial force of 2.5 kN Δgap max ̴2 µm Max. Stress 3 MPa Δdeflection ̴10.8 µm

  15. Conclusions • On the basis of FEA performed, the selected clamping force is 2.5 kN, which corresponds to a tightening torque of 7.5 Nm • According to the results, the reduction of initial flanges gap (50 µm) due to the applied load is negligible. • The results show that larger clamping forces do not have significant influence on the transversal deflection of PETS. Anyway, this elastic deflection will be completely recovered once the structure is supported on the designed supports for TM0. • The highest stresses occur around the contact area close to the edge inside the adapter disk. For a clamping force of 2.5 kNthe maximum value is less than 3 MPa (σY = 69 MPa)

  16. EBW tooling for PETS • Introduction • General description • Assembly on tooling • Transportation • EBW process • FEA • Loading and Boundary Conditions • Results • Conclusions • Brazing tooling for AS • Introduction • General description • Brazing process • Assembly on tooling • FEA • Loading and Boundary Conditions • Results • Conclusions

  17. General description Accelerating structure Super-accelerating structure Vacuum flange 484 RF flange Target sphere Cooling circuit 2031 RF waveguide Manifold 334 Interconnection flange

  18. Brazing process BRAZING (Au/Cu 25/75, 1040 °C) WFM WG cover + WFM WG body (x32=4x8) Waveguide damping interface half 1 + half 2 (x32=4x8) Stack type 1 (x6) Stack type 2 (x1) Stack type 3 (x1) Manifold cover (tank int.) + vacuum tube P1 (x8) Manifold small cover 3 + small cover 3 insert (x32=4x8) MACHINING WFM WG brazed (x24=3x8) WG dampinginterface (x16=2x8) TIG WELDING Manifold cover 2 assembly (x8) BRAZING (Au/Cu 25/75, 1040 °C) Manifold (hor) assembly (x8=1x8) Hor. manifold (mirrored) assembly (x8=1x8) Vert. manifoldassembly (x16=8x2) BRAZING (Au/Cu 35/65, 1020 °C) Structuretype 1 (x6) Structuretype 2 (x1) Structuretype 3 (x1) BRAZING (Au/Cu 50/50, 980 °C) Brazedstack 1 + AS coolingfittingadapters Brazedstack 2 + AS coolingfittingadapters

  19. Brazing process 1020 °C 900 °C Temperature history

  20. Assembly on tooling • Lower plate (graphite): support the assembly during alignment operations and brazing cycle. • Wedges (ceramic): allow small adjustment of manifolds in the vertical direction. • Lateral springs (graphite): apply an horizontal force to the manifolds through the lateral plates and allow thermal expansion of the assembly during the brazing cycle (k=20 N/mm). • Lateral supports (stainless steel): support the springs. Upper support Upper spring Lateral plate Nut Lateral spring Rod Lateral support • Upper spring (graphite): apply a vertical force on the manifolds through the upper support and allow thermal expansion of the assembly during the brazing cycle. • Rod (stainless steel): connect upper support and lower plate. Wedges Lower plate

  21. Assembly on tooling 1. Graphite plate 2. Disks stack 3. Wedges 4. Manifolds 5. Lateral supports, plates and springs 6. Upper support 7. Rod 8. Upper spring and nut

  22. FEA • A static thermal and structural analysis with a temperature variation from 20 °C • to 1020 °C was carried out for the accelerating structure • The thermal expansion is constrained only by the springs, which are situated on the opposite sides of the fixed lateral support • All the connections were considered ideally frictionless to reduce the computational time Tooling for the 1st brazing step Free surfaces constrained by the springs Fixed surfaces connected to the lateral support (without springs) For the springs a constant stiffness of 20 N/mm was used Supported on the ground

  23. Results – thermal expansion Max. in y-direction 7.2 mm Max. in x-direction 4.6 mm z y x Max. in z-direction 5.3 mm

  24. Results – stresses Max. 0.1 MPa Stress due to thermal expansion

  25. Conclusion • On the basis of the FEA the displacements and the stresses due to thermal expansion have been calculated • The transversal displacement of the manifolds is approximately 5 mm • The axial displacement of the whole structure is approximately 5 mm • During the brazing process the calculated stresses are below the copper yield strength at 1020 °C (σY = 7.5 MPa) • Future work • Transient thermal analysis to model the temperature history • Thermal and structural simulations for the brazing of 4 AS • Structural analysis for the AS intermediate EBW tooling

More Related