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## Quantifying the force due to electrostatic pressure via the maxwell stress tensor

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Edward Principe

July 27, 2013 10:15pm UTC

Quantifying the force due to electrostatic pressure via the maxwell stress tensor

I hope this is a easy question to answer because I know there must be a way to obtain the numerical output for the forces created by electrostatic fields.

I have produced an ES model with similar polarity voltage between two conductive bodies. This creates a repulsive force which I modeled as a boundary load (solid mechanics) on the surfaces due the electrostatic forces calculated through the variables es.unTez, es.unTey and es.unTex.

I can then even model the deflection based upon these forces. That all seems to work.

Now I would like to know in an easy way, how to determine the numerical value of force on each surface (and also the resulting deflection for that matter). The data must be there, I just can't figure out how to display it.

For instance, let's say I want to integrate the surface stress over one of the geometries in question and determine the resultant force in Newtons. Seems reasonable.

How does one determine these actual values??

Thanks!

-Ed

Edward Principe

July 28, 2013 12:03am UTC in response to Edward Principe

Re: Quantifying the force due to electrostatic pressure via the maxwell stress tensor

Okay, I think I found my own answer - at least in part.

Under "derived values" in the results section you can define the surface integral using the expression es.unTx, which is the Maxwell stress tensor.

What concerns me is this singular value is identical no matter what boundaries I choose to evaluate. It is the same numerical value everywhere. So the question is: what surfaces is it integrating over if it is independent of the ones I select in the model?

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