Polycarbonate Water Tank

[intavent]

Before I head off to my local engineer to discuss, can anyone assist me with this project. I have been asked to fabricate a clear tank measuring 1200m x 1200mm x 1200mm. The tank is to be filled with water to observe and video various items being dropped into water. Among the items to be dropped into this tank is a person so it may be described as a dunk tank. Preferred material is 12mm Macrolan uv2 solid Polycarbonate sheet cut and welded to form an open top cube which will sit in a steel cube frame. The steel cube frame is to be manufactured from 6mm thick angle iron with 50mm and consists of a square sections top and bottom and 4 vertical sections to complete the cube. Minimal clearance between the polycarbonate cube and the steel cube frame. My question is - will this tank design of 12mm polycarbonate and angle iron frame be able to maintain its shape and integrity when filled to the top with 1728 litres of water. Many thanks.

 

[JStephen]

For your specific question, you need to head off to your local engineer to discuss.
First question is, what are the mechanical properties of that polycarbonate material? It's not uncommon to have difficulty finding good information on stuff like that.
It seems to me that if that material can fail in a brittle fashion, you basically have an aquarium. I don't know if they are actually "designed" or if the thickness of materials used are just based on experience. There may also be information relating to glass panels used in handrailing and whatnot- I've seen some threads on that application in the "Structural Engineering- other technical topics" in the past.
If that material does not fail in a brittle fashion, you could design it like a square steel tank, using flat plate equations in Roark's Formulas for Stress and Strain or other similar references.
If that material is normally used for aquariums, you may find information from the producer as to thickness required for specific sizes, depths, etc.
Normally, aquariums and tanks are used in ways where the filling operation is fairly slow and steady- you're not dropping large items in to watch the splash. So it occurs to me that you could get some impulse forces on the sides of that tank that are a good bit higher than what would be assumed in a static tank. So you may wind up with a "if in doubt, make it stout" situation.

 

[LittleInch]

Also what sort of Accra are you looking for in terms of shape preservation? 1%, 0.1%, ??

What is "minimal" clearance?

The cube joints appear critical and SCF substantial.

But maybe that's how tanks are built, but don't ignore the shock loading issue.

1200 deep looks too small to drop a person in it...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IFRs]

Determine the loads, calculate the stresses, analyze the components and examine the connections. As an engineering professional this should be your normal practice. When you run into specific questions, folks here will be happy to help but this is your project, your responsibility.

 

[chicopee]

For the walls apply the flat plate equation for three simply supported edges and for the bottom for a plate with four simply supported edges. Deflection equation will probably predominate over stress equation, anotherword, by limiting the deflection, the stresses should be very low.

 

[intavent]

Thank you for your replies. My role in this project is to gather information and ideas from the engineering community and to write a descriptive brief for local engineers. You've all added value and I thank you sincerely for your input.