Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.
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Transcript of Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.
![Page 1: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/1.jpg)
Preliminary ANSYS Results:CCD Fixture and Lens Frame
Andrew Lambert
![Page 2: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/2.jpg)
Outline
• CCD Results– Temperatures– Deformations– Conclusions
• Lens Frame Results– Vertical Orientation Deformation– Horizontal Orientation Deformation– Deformation due to Thermal Expansion– Conclusions
![Page 3: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/3.jpg)
Thermal BC’s
• Radiation to 22 oC • Fixed Temperature of -120 oC on Focal Plane• Heat Flow of 110 mW at each corner• Heat Flow of 20 mW where Flex Strips attach
![Page 4: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/4.jpg)
Temperatures
Aluminum Invar
SiC
![Page 5: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/5.jpg)
Deformation of CCD
Base MaterialFocal Plane Temp
(oC)ΔT Focal Plane to
CCD (K) Max Stress (MPa)Max CCD Deformation
(µm)Y-direction Deformation
(µm)Al -124.5 (-122.0) 4.5 (2.0) 102.5 (106.3) 16.5 (14.4) 14.5-14.7 (12.1-12.3)Invar36 -127.5 (-124.5) 7.5 (4.5) 14.5 (18.32) 8.9 (8.7) 5.2-5.3 (4.9-5.0)SiC -122.5 (-120.7) 2.5 (0.7) 8.8 (12.6) 8.2 (8.2) 4.0-4.2 (4.1-4.2)
Note: Values in () indicates Moly spacer instead of Invar
Aluminum Invar
SiC
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CCD Simulation Conclusions
• Aluminum performs the worst in terms of stress and deformation
• Invar and SiC have similar mechanical performance, however SiC has better thermal conduction and hence is better suited for cooling.– A ΔT of 20 K was the worst case scenario, and both Invar and SiC are
better than this• Note: thermal contact points are modeled perfectly, which will not be the case
in reality.
• Overall, the best material for use is SiC, however; using Moly spacers with Invar greatly improves thermal conduction from the base to the CCD – makes it competitive with SiC
• The best combination was a SiC focal plane with Moly spacers
![Page 7: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/7.jpg)
Structural BC’s
• Fixed supports where frame attaches to focal plane• Standard Earth gravity
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Lens Frame - Vertical
Note: The deformed lens shape is exaggerated!
Invar
Titanium
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Lens Frame - Horizontal
Note: The deformed lens shape is exaggerated!
Invar
Titanium
![Page 10: Preliminary ANSYS Results: CCD Fixture and Lens Frame Andrew Lambert.](https://reader030.fdocuments.us/reader030/viewer/2022032723/56649d0e5503460f949e3584/html5/thumbnails/10.jpg)
Thermal BC’s
• Fixed Temperature of -120 oC where frame attaches to focal plane
• Radiation to 22 oC • Radiation to -120 oC
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Thermal Expansion
Invar
Titanium
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Lens Frame Simulation Conclusions
• The Titanium and S-LAH59 combination does not perform well structurally– If this combination is used, we need to “beef up” the lens frame
considerably– S-LAH59 is much heavier than the Fused Silica
• Invar36 and Fused Silica perform much better• Neither model has high stress – no failure modes• Invar36 and Fused Silica seem to be the best option going
forward.• No matter which combination is used, I would recommend
reinforcing the lens frame structure
Frame Material
Lens Material
Vertical Deformation (µm)
Horizontal Deformation (µm)
Max. Thermal Deformation (µm)
Titanium S-LAH59 1.3 31.3 545.6Invar36 Fused Silica 0.6 16.7 94.9