Would a 4'x8'x1' piece of glass be able to contain 60psi?

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In summary, the design is for a block of glass that can hold 1 atm of pressure. The thickness of the glass is not related to the pressure, but the maximum pressure is.
  • #1
Physt
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Preface: This isn't an actual project, just trying to get the design to be realistic for a 3D model in a video game.

I know most pressure vessels are round and the overall shape of this one would be round, but it's very large (about half a football field large) so it would be composed of a bunch of panels. The 4'x8'x1' piece of glass would be supported evenly on all four 1'-wide sides by being clamped into a support 1.5 inches deep (so the actual surface area would be 45"x93").

Would this be good enough to hold 60psi (actually 1atm, but from what I've read about double the pressure is a good design parameter to go by)?

What would be the maximum pressure of this design?

Does anyone happen to have the equations for a calculating the maximum pressure allowable for flat panels like this so I might plug different materials into the equations?
 
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  • #2
~30cm thick? That is a massive block of glass. The biggest window at the ISS has a diameter of 80cm and is just 2.5 cm thick (there are two glass panes behind each other so one serves as backup) - and I'm sure they have a huge safety margin built in.
 
  • #3
mfb said:
~30cm thick? That is a massive block of glass. The biggest window at the ISS has a diameter of 80cm and is just 2.5 cm thick (there are two glass panes behind each other so one serves as backup) - and I'm sure they have a huge safety margin built in.

From all I've fathered thus far the thickness of the glass grows quite a bit relative to the length of the shortest dimension. ~30cm is my best guess thus far based on the calculators available online for curved surfaces at approximately 122cm across with a little more for the sake of it being a flat surface.

The best calculator I've found online thus far for glass panels is http://www.dullesglassandmirror.com/glass-shelf-weight-load-calculator.aspx and a 45"x93" piece of tempered glass with a thickness of 1" and supports at 48" (closest I could get to supported along all four edges with that calculator) it comes in at 9416.25 lbs max, so divided by (45*93) yeilds 2.25psi, 27psi for 12" of thickness. So if that estimate is close it wouldn't quite be thick enough (without even doubling the psi for the sake of safety).

Guessing (hoping) that's not an entirely accurate estimate though.
 
  • #4
The allowed pressure does not scale linearly with thickness. The square is a better estimate, so 12 times the thickness gives 144 times the pressure - a good safety factor with your values.

I really don't like weird and exotic unit systems.
 
  • #5
mfb said:
The allowed pressure does not scale linearly with thickness. The square is a better estimate, so 12 times the thickness gives 144 times the pressure - a good safety factor with your values.

I really don't like weird and exotic unit systems.

Thanks, I too dislike the English system, but if one were to buy a large sheet of glass in the US it would likely be a 4'x8' pane - same goes for layered glass/polycarbonate stacks - so figured I'd try to work around that.
 

1. Would a 4'x8'x1' piece of glass be able to contain 60psi?

It depends on the type and thickness of the glass. Generally, a 1-inch thick glass can contain up to 1300 psi. However, it is important to consider the quality and condition of the glass as well.

2. How do you calculate the pressure that a piece of glass can withstand?

The pressure that a piece of glass can withstand is determined by its Young's modulus, which is a measure of the stiffness of the material, and its thickness. The formula for calculating pressure is pressure = (Young's modulus x thickness) / 2. For example, a 1-inch thick glass with a Young's modulus of 10,000 psi can withstand a pressure of 5,000 psi.

3. Is the size of the glass important in determining its ability to contain pressure?

Yes, the size of the glass is an important factor in determining its ability to contain pressure. The larger the surface area of the glass, the more force it will experience, making it more likely to break. Additionally, larger pieces of glass may have weaker points, such as corners, that are more susceptible to breaking under pressure.

4. Can the method of installation affect the glass's ability to contain pressure?

Yes, the method of installation can play a significant role in the glass's ability to withstand pressure. If the glass is not properly supported or installed, it may be more prone to cracking or breaking under pressure. It is important to follow proper installation techniques and to use appropriate support structures when dealing with high-pressure environments.

5. Are there any other factors that can affect a piece of glass's ability to contain pressure?

Yes, there are several other factors that can affect a piece of glass's ability to contain pressure, including the quality and condition of the glass, the type of pressure being applied (static or dynamic), and the temperature of the environment. It is important to consider all of these factors when determining the maximum pressure that a piece of glass can withstand.

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