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Large deformation issue
Posted 2010年4月27日 GMT-4 08:06 0 Replies
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I'm facing a few problems while attempting electrostatic actuation of a fixed-fixed membrane.
But let's start with the most puzzling issue:
Consider a 2D model (plane stress + moving mesh) with a thin and long membrane (1µmx300µm) fixed at both extremities and surrounded by air. I apply a load to the lower boundary of the membrane so that it deforms no more than 4µm vertically (maximum total displacement).
Well, I obtain very different results when the "Large Deformation" option is ON or OFF.
When ON, I observe a linear increase of max displacement with load, and when OFF the displacement is much smaller and more asymptotic.
I would think that a displacement of max 4µm for a 300µm long film is consistent with a small deformation and in that case, I really don't understand why the difference!! I can't find how this option affects the equations...
Moreover if then I want to introduce "initial stresses" in the membrane, then the amount of stress has absolutely no effect on the maximum displacement in the OFF case, and a huge effect in the ON case!
If anyone can provide an explanation, it would really help, because otherwise I'm stuck!
Thank you
Elodie
Hello elodie leveugle
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