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Greetings SMMOMS,
I've been analyzing the original acrylic blown dome, that came on my KL-250, and made the assembly model of it, to put on the CAD assembly of the whole sub as it was configured when I received it. Then later I'll put a modified version of it on a assembly model of the K-250 as it is configured in the Captains plans.
I've noticed that the bonded on rim ring on my dome is made up of four strips of .25" thick by .75" wide acrylic joined at a 45 degree angle. The thickness at the apex of the dome is just under 3/8" . I'm working of obtaining the exact shape of the dome, but currently I think have a reasonably good facsimile. I've begun to run some FEA testing on the dome assembly I currently have worked up. No surprises there so far, with the higher stresses being on the thin top area, and the inside seating area. I still need to obtain a few material property specs on the Acrylite G and Polycast cell cast acrylic to obtain more accurate data. The CosmosWorks software I use has a cyclic fatigue analyzing engine, so I'll have to put it to good use.
My rendering software and computer were playing nice together, for this session, so some interesting renderings came out, with out me feeling like pulling out my hair. ; }'
I can clearly see on the old dome that it was retained in two different positions about it's axis. It was held in one position for a long time, and I could see where the metal holding cleats pressed against the outer surface of the blown dome. This makes me think that for this type of dome, that there could be a retaining ring with a rubber gasket under it, instead of the metal cleats. I see Alec changed his out for plastic ones.
Alec, are those made out of UHMW?
Also in both said holding positions, there is fracture damage to the blown dome. One area in particular took some serious damage. Some of fractures might be from tightening the cleats down to hard, and/or the hatch was dropped or obtained the damage in a particular holding position when the sub suffered a hydrogen explosion inside and blew back the hatch with out it being latched inside or out.
Regards,
Szybowski