Thank you everyone for your suggestions. This has been very informative and helpful.
Based on the responses and some more research into this topic, I came up with the following theoretical conclusions:
Regarding the triangular plate, it could crack due to the following possible reasons:
-Mechanical load applied on the support
-Loads due to stresses due to thermal cycling
-Material that could not withstand either of these of both
I am attaching images that show the triangular plate and a stack of clear plates that also mechanically support the crystal. These stack of clear plates fit tightly in the bore of the detector's end cap.
- Image showing stack of clear plates at the detector's end cap
- Image showing both the supports
As a final step in this case study, I am trying to design a new crystal support system using Solidworks. This new design has to satisfy the following constraints:
- Survive when handled roughly (
should not crack)
- Withstand different temperatures (cryogenic temperatures, 100 C bake, thermal cycling)
- Provide
insulation
- Minimize
material outgassing
- Should be
installable in existing detectors that have this cracked plastic plate problem
The last point is a major constrain that has to be taken into consideration. Based on this problem statement that was given to me, I am attaching a file that shows my interpretations regarding the last constraint. Since it has to be installed on existing designs, the following image shows some parameters that will stay in the new design.
- Image showing some design related constraints
New design ideas:
1) Mechanical support:
As I have mentioned in previous post, the triangular plate cracks even with gentle handling. Hence, assuming that the load is not uniformly distributed in the existing design, I was planning to include another layer in between the top and bottom layer to provide more support. I have included a figure where I would have pointed out this for better understanding.
2) Materials used:
Based on various suggestions, I shortlisted the following materials to be taken into consideration for the new design and chose the best material by comparing their ability to meet the constraints (withstand mechanical and thermal loads):
-Polycarbonate
-Plexiglas
-Ceramic
-Teflon
-G10
3) Design process:
I have drawn 5 more sketches in a similar fashion, and with different arrangements. To design in solidworks, I will be choosing the one design that satisfies all constraints. In the image that shows one of my sketches, I included a middle layer thinking that it would not fail because of the weight of the system.
I am not sure how my design works when it comes to withstanding thermal loads as a result of cycling and fatigue (repeated expansion and contraction). I am sure the material has a role to play. However, I was wondering if there is any way by which the thermal loads can be minimized using mechanical supports, i.e., can this be designed in way where the thermal loads acting on it are minimal?
Please let me know your feedback and suggestions on my design process. I would love to get your inputs. It would be helpful if you can suggest some references and also provide your ideas on what you feel would be the best to do for this system.
Thanks,
Ashish