pressure vessel windows

[bulldo]

Hello,

I need some advice on basic calculations to determine pressure vessel window deformation and failure depth.
I need to be able to do this analysis myself so outsourcing to a third party design/FEA house is not an option.

Does anyone know of any source/guide on this subject - at present i am just analysing a simple round window.

Thanks

 

[arto]

Look in ASME PVHO "Pressure Vessels for Human Occupancy"

 

[VeryPicky]

Are yoy talking about a "window repair"?

Putting Human Factor Back in Engineering

 

[hacksaw]

failure depth? are you designing a submesible?

 

[bulldo]

Hi - its a relative small cylindrical aluminium housing (approx 50 mm by 50 mm) with a perspex window in the end designed to go underwater.

I need it to be able to go down to 3km at least (maybe even 6km)

I was thinking of using a 25mm thick by 50 mm diameter window and need to do some safety calculations regarding the failure depth.

 

[JStephen]

Do you have allowable stresses or failure criteria for the window material?

You can check shear in the window by summing forces on a circular section cut from the center. You can get an idea of bending stresses from the flat plate formulas in "Formulas for Stress and Strain" or other handbooks. They're not necessarily applicable to a "thick" plate, but should be good for ballpark answers.

I would think a major part of the problem would be dealing with the support at the edges and the stresses there, though.

 

[arto]

Also check out:

PVHO-2 - 2003 Safety Standard for Pressure Vessels for Human Occupancy: In-Service PVHO Acrylic Windows Guidelines

http://members.asme.org/catalog/ItemView.cfm?ItemNumber=A15403

"This Standard provides technical criteria and guidelines for the in-service inspection, care, repair or replacement, testing, and recertification of PVHOacrylic windows in Pressure Vessels for Human Occupancy. It is intended to be used only with acrylic windows designed, constructed, tested, and certified in accordance with the requirements of ASME PVHO-1, Safety Standard for Pressure Vessels for Human Occupancy. This Standard provides technical criteria for the user to establish the serviceability of a PVHO acrylic window under its specific environmental service conditions. Windows in protected environments as well as those in severe environments are addressed. Judicious use of this Standard will allow the user and/or the jurisdictional authority to determine when a PVHO acrylic window requires replacement. "

PVHO-1 is @

http://members.asme.org/catalog/ItemView.cfm?IMAGE.X=25\&IMAGE.Y=9&ItemNumber=A09202