CERN, the 9th of Nov FEA Updates on Structures (overall ID model) University of Geneva: G. Barbier, F. Cadoux, A. Clark, D. Ferrère, M. Weber ATLAS Upgrade Week CERN, of November 2009

CERN, the 9th of Nov RECALL of the FE model features [1] Overall CAD model of ID (part descriptions…PIXEL, Strip BARREL, 2 End Cap, services, Outer Cylinder) End flange Outer Cylinder (OC) 6.3 m End Cap (EC) Barrel Pixels

CERN, the 9th of Nov RECALL of the FE model features [2] Baseline used for simulations: PIXEL attached to Barrel (as a lumped mass of 300Kg total) Pixels Barrel: 5 concentric cylinders Per side: 8 interlinks, 4 Superlinks Pixels Services for both Pixel and Barrel (100Kg per side) Pixel Mass location (150 Kg per side) Needs soon a first mechanical model for Pixel

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: BARREL geometrical model (made of surfaces) 5 cylinders (single skin material) with reinforcing rings 4 Superlinks (to Outer Cylinder) 8 Interlinks (3mm thick) Bare weight: 103 Kg (no STAVE) from both CAD and FEA…1mm thick

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: Lumped mass to be added onto the BARREL STAVE weight (720 Kg total) As follows: -Barrel1: 100 Kg -Barrel2: 130 Kg -Barrel3: 150 Kg -Barrel4: 150 Kg -Barrel5: 190 Kg Ex: Barrel1 lumped mass (surfaces in red) Service weight (200Kg total) 100Kg per side

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: END CAP (EC) geometrical model (made of surfaces) Inner cone: CFRP material/ 0.5mm thick Outer cylinder: Honeycomb 0.3mm CFRP facings / 10mm Nomex core EC feet: CFRP material / 4mm thick DISK 1 DISK 2 DISK 3 DISK 4 DISK 5 EC Disks: All in honeycomb 0.3mm CFRP facings / 10mm Nomex core

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: Lumped mass to be added onto EC surfaces STAVE weight (100 Kg total) Applied to the 5 Disks (proportional to the surfaces) EC Services weight (100 Kg total) Applied to the Outer cylinder

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: Outer Cylinder (OC) geometrical model Outer Cylinder (OC): Honeycomb 2.5 mm CFRP facings / 30mm Nomex core OC End Flange Honeycomb 1 mm CFRP facings / 20mm Nomex core Close up on the ties between OC and its flanges Shape given by service cross section

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: Outer Cylinder lumped mass…Polymoderator and services Polymoderator weight (316 Kg total) Applied to the middle part Service weight (500 Kg total) Applied to both ends

CERN, the 9th of Nov Model description & Weight assumptions Baseline used for simulations: The overall CAD model (all made of surfaces elements) OC Barrel EC

CERN, the 9th of Nov Material mechanical features (CFRP & Honeycomb) CFRP material (Quasi Isotropic facing, density=1,6) Honeycomb is assumed to be in Nomex

CERN, the 9th of Nov FEA Overall Model (meshing) 3D model Model total mass: (given by FEA) M= 3043 Kg

CERN, the 9th of Nov FEA Outcomes [With OC End flanges; BC#1] Sagging Uy = 1.24mm Barrel / 0,4mm OC Von Mises stresses: 93 MPa Barrel links Outer BC’s (handling/cryostat): 4 pts (simply supported) EC and Barrel fixed by 4 pts / OC (2 per side)

CERN, the 9th of Nov FEA Outcomes [With OC End flanges; BC#2] Sagging Uy = 0.7mm Barrel Von Mises stresses: 49 MPa EC fixed by 4 pts / OC Barrel fixed 6 pts / OC (3 per side)

CERN, the 9th of Nov FEA Outcomes [Without OC End flanges; BC#1] Sagging Uy =1.34mm Barrel / 0.4mm OC Von Mises stresses: 92 MPa (Barrel) EC and Barrel fixed by 4 pts / OC (2 per side)

CERN, the 9th of Nov FEA Outcomes [MODAL shape & Eigen value 1] z Modal Shape: Barrel movement along z axis with a slight twisting (freq. : 9 Hz)

CERN, the 9th of Nov FEA Outcomes [MODAL shape & Eigen value 2] z y Modal Shape: Barrel movement along y axis (freq. : 20 Hz)

CERN, the 9th of Nov FEA studies Conclusions and Outlooks  No big issue up to now (Deflection/Stresses of the Barrel can be reduced by a 3 rd point)  Still need to investigate: The EC design (new baseline ?) The BARREL behavior in case of a DISK conceptual design The PIXEL design to be implemented into the FE Model  Still need to understand/estimate the relative deformations within each detector (what sagging is acceptable for physics?) This FE model is only to give a first feedback/feeling about the overall behavior (rigidity). And to play with different conceptual designs for cross comparisons. Fine tuning on parameters (material, meshing,…) will be done as soon as the designs are more “realistic”…