Running multiple studies in COMSOL

[fkhan]

Hi. Can anyone help me to figure out how to run multiple studies in COMSOL? I want to first compute the displacement of a membrane using temperature load and then find the capacitance between two electrodes using electrostatics. The idea is that as the membrane moves upwards the capacitance will decrease (the top electrode of capacitor is on top of the membrane). Given that i need to find B using the results of A I think I should use 2 studies but even when i select only thermal stress and electromechanics for study 1 it still doesn't provide the right solution if electrostatics study is added to the model. But if i use thermal stress and electromechanics without electrostatics in the model it gives perfect results. That makes me conclude that even after removing electrostatics from the study it still uses some variables from it which mess up the calculations. I've tried everything i could think of so any help would be appreciated.

 

[DrClaude]

I guess that electrostatics and electromechanics interact strongly with each other, so it might not be a bug that makes the result different if the electrostatics module is added. You should make sure that properties of all elements are correct.

If you electrostatics is used only to calculate the capacitance, couldn't you do it from within electromechanics? I am not familiar with that module, but there might be a way to calculate the capacitance by measuring the accumulated charges using Gauss's law.

 

[fkhan]

electromechanics physics is a combination of 2 physics (electrostatics and solid mechanics). I understand what you're trying to say but don't you think if i remove the electrostatics from the study comsol should use only thermal stress and solid mechanics to cause deflection? well that's not what's happening. As soon as i add electrostatics to the model (even if i don't add it to the study or remove it from the study) it causes severely improper results.