Failing point of a lexan spheres?

In summary, the person is asking for calculations regarding the submersion, dropping, and buoyancy of lexan plastic spheres in sea water. They also inquire about the stress and impact resistance of the spheres. The conversation ends with the advice to seek help from a professional engineer for projects with life-safety implications.
  • #1
aussie101
11
0
Hi
I'm a newby and have a project way out of my depth where a wrong calculation will be fatal...

I need calculations of :

1.how far a 2500mm and 3000mm sphere of lexan plastic 50mm thick can be submerged in sea water before it will implode/fail (in meters)? See data below.

2.From what height can the either sphere be dropped from onto the sea water surface tension before failing?

3.How much weight (kg) would it take to make the spheres neutrally buoyant (neither sink or float)?

4.Can the stress formed in process (inside the sphere) be calculated and ratio to the above calcs? (e.g. For every mpa stress in structure will reduce the mpa of impak or pressure resistance/rating)

MECHANICAL
Tensile Stress, yld, Type I, 50 mm/min 590 kgf/cm²
Tensile Stress, brk, Type I, 50 mm/min 580 kgf/cm²
Tensile Strain, yld, Type I, 50 mm/min 5.7 %
Tensile Strain, brk, Type I, 50 mm/min 117.9 %
Tensile Modulus, 50 mm/min 23000 kgf/cm²
Flexural Stress, yld, 1.3 mm/min, 50 mm span 960 kgf/cm²
Flexural Modulus, 1.3 mm/min, 50 mm span 22900 kgf/cm²
Tensile Stress, yield, 50 mm/min 57 MPa
Tensile Stress, break, 50 mm/min 56 MPa
Tensile Strain, yield, 50 mm/min 5.4 %
Tensile Strain, break, 50 mm/min 119.4 %
Tensile Modulus, 1 mm/min 2340 MPa
Flexural Stress, yield, 2 mm/min 89 MPa
Flexural Modulus, 2 mm/min 2140 MPa
IMPACT
Izod Impact, notched, 23°C 75 cm-kgf/cm
Izod Impact, notched, -30°C 63 cm-kgf/cm
Instrumented Impact Total Energy, 23°C 763 cm-kgf
Izod Impact, notched 80*10*4 +23°C 47 kJ/m²
Izod Impact, notched 80*10*4 -30°C 24 kJ/m²
Charpy 23°C, V-notch Edgew 80*10*4 sp=62mm 61 kJ/m²
Charpy -30°C, V-notch Edgew 80*10*4 sp=62mm 17 kJ/m²
 
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  • #2
You are not going to get help here with projects that could have life-safety implications. You need to engage a professional engineer to help with projects like that.

Thread closed.
 

1. What is the failing point of a lexan sphere?

The failing point of a lexan sphere refers to the point at which it can no longer withstand external pressure or force, causing it to break or deform. This can vary depending on factors such as the size and thickness of the sphere, as well as the type and amount of pressure applied.

2. How is the failing point of a lexan sphere determined?

The failing point of a lexan sphere is typically determined through experiments and tests, where the sphere is subjected to increasing amounts of pressure until it reaches its breaking point. This can also be calculated theoretically using mathematical models and equations.

3. What factors can affect the failing point of a lexan sphere?

The failing point of a lexan sphere can be affected by various factors such as temperature, impact force, and surface quality. For example, a sphere made of lower quality lexan material may have a lower failing point compared to one made of higher quality material.

4. Can the failing point of a lexan sphere be increased?

Yes, there are ways to increase the failing point of a lexan sphere. One way is by increasing the thickness of the sphere, which can help it withstand more pressure. Another way is by using a higher quality lexan material, as mentioned earlier.

5. What industries or applications commonly use lexan spheres?

Lexan spheres are commonly used in industries such as aerospace, automotive, and engineering for various applications such as pressure vessels, impact-resistant windows, and protective coatings. They are also used in research and development for testing and experimentation purposes.

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