Stress calculations for acrylic

In summary, for an acrylic panel to be used in a vertical position as a window for a large aquarium, with a maximum design stress of 800 PSI and a maximum water pressure of 2.6662 PSI, the required material thickness would be 0.4 inches. This calculation is based on the force of 324 pounds pushing the panel outwards and taking into account the mechanical properties of acrylic. However, a more precise stress analysis using a computer model would be recommended for accurate results.
  • #1
bigfish2000
4
0
I need a formula for deriving the required material thickness for an acrylic panel.

The project will involve an acrylic window for a large aquarium. I have included a dimensional rendering.

The maximum design stress must be maintained at or below 800PSI.

The maximum water pressure inside the aquarium will be 2.6662 PSI above atmospheric.

The panel will be used in a vertical position as detailed in the rendering.

The load force (wet) will be on the concave side.

The panel will have concrete support along all four edges as outlined in gray. The viewing portion is shown translucent in the rendering.

The mechanical properties of acrylic are as follows.

Tensile strength: 10,000 PSI
Elongation, Rupture: 4.2%
Modulus of Elasticity: 400,000 PSI

Flexural Strength: 16,500 PSI
Modulus of Elasticity: 475,000 PSI

Compressive Strength: 18,000 PSI
Modulus of Elasticity: 430,000 PSI

Shear Strength: 9,000 PSI

Impact Strength .4ft lbs/in

Rockwell hardness: M-94

If you need any additional information please let me know.

Thank you for the assistance.
 

Attachments

  • #1.jpg
    #1.jpg
    13.9 KB · Views: 826
  • #2.jpg
    #2.jpg
    14.6 KB · Views: 881
Engineering news on Phys.org
  • #2
If you think about a horizontal "slice" one inch deep at the bottom, the water pressure is about 2.7 psi (that's about right for 6 feet of water). So the force pushing the panel outwards is 2.7 psi x 1 inch x 120 inches width = 324 pounds.

So if you want to limit the stress to 800 psi, you need a total thickness of 324/800 = 0.4 inches of acrylic, i.e a 0.2 inch thick plate (because there are two sides resisting the force).

Note, that is a very over-simplified calculation. You would also need to consider the stress in the joint between the bottom of the acrylic sheet and the base of the tank, which is a much more complicated issue. Personally I would do a stress analysis using a computer model (i.e. finite element analysis), rather than trying to find a "formula"
 

1. What is the purpose of stress calculations for acrylic?

The purpose of stress calculations for acrylic is to determine the maximum amount of stress that the material can withstand before it deforms or breaks. This is important in engineering and design to ensure the safety and reliability of structures or products made from acrylic.

2. How are stress calculations for acrylic performed?

Stress calculations for acrylic are typically performed using mathematical equations and formulas that take into account the physical properties of the material, such as its tensile strength, elastic modulus, and yield strength. These calculations can also be done using computer software or simulation tools.

3. What factors can affect the stress calculations for acrylic?

Several factors can impact the stress calculations for acrylic, including the shape and size of the acrylic piece, the type and amount of load applied, temperature, and the presence of any defects or imperfections in the material. It's important to consider all of these factors to get an accurate stress calculation.

4. How do stress calculations for acrylic differ from other materials?

Stress calculations for acrylic are unique to this material because it has its own unique properties and behaviors. For example, acrylic is typically more brittle compared to other materials like steel, so it may have a lower maximum stress limit. Additionally, the way stress is distributed and absorbed within the material may also differ.

5. How can stress calculations for acrylic be used in real-world applications?

Stress calculations for acrylic are essential in various industries, such as construction, automotive, and aerospace, where this material is commonly used. By accurately calculating the stress limits, engineers and designers can ensure the safety and durability of structures and products made from acrylic, leading to more reliable and long-lasting results.

Similar threads

Replies
1
Views
1K
  • Mechanical Engineering
Replies
2
Views
9K
  • General Engineering
Replies
3
Views
8K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
3K
Back
Top