1. ## Calculating Total Deflection for Constant Load

Hi All,

Newbie here ... I am trying to find an equation to calculate what the total compressed distance would be for a sheet of silicone rubber under a constant load with a known surface area.

I am not a ME, but am involved in a project where I need this type of info. Any help would be greatly appreciated!

Thanks,

Ed

2. If you look for the easiest model I think Hooke's law can apply: ΔL = (L0 * F) / (S*E)
ΔL--> deformation, strain
L0--> sheet thickness
S--> surface aera
E--> Young's Modulus of your material
This model is extremly simplified thought, more detailed researches are needed if you look for something serious.

This is in the case where your material has the space freely deform itself (it's not "compression" but "deformation").

If you material is completely blocked from all sides, then the force you apply will act as an Isostatic Compression, and in this situation there is actually compression of your material, and the law is different.
The formula: ΔV = (ΔP*V0) / -K
V --> Volume, P--> Pressure
K --> Bulk modulus of your material

Basically your silicon sheet will deform itself until it fills all the space avalaible and then it will compress itself.

3. Originally Posted by Foudzing
If you look for the easiest model I think Hooke's law can apply: ΔL = (L0 * F) / (S*E)
ΔL--> deformation, strain
L0--> sheet thickness
S--> surface aera
E--> Young's Modulus of your material
This model is extremly simplified thought, more detailed researches are needed if you look for something serious.

This is in the case where your material has the space freely deform itself (it's not "compression" but "deformation").

If you material is completely blocked from all sides, then the force you apply will act as an Isostatic Compression, and in this situation there is actually compression of your material, and the law is different.
The formula: ΔV = (ΔP*V0) / -K
V --> Volume, P--> Pressure
K --> Bulk modulus of your material

Basically your silicon sheet will deform itself until it fills all the space avalaible and then it will compress itself.
Thanks Foudzing! This should help.

Ed

4. You're welcome, oh and I forgot to tell you: if you exceed the maximum elasticity pressure, you'll go in plasticity deformation and your material will never go back to it's original state, so that can be a problem depending on what do you use this silicon sheet for.

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