Discussion Forum

Hi,
So I'm pretty new at COMSOL, and I'm struggling with linking two different physics/studies. Specifically, I'm hoping to look at the effect of an external magnetic field on the resonant frequency a very long and narrow CoFe bridge. I've been able to create the magnetic field, in 2D with the Magnetic Fields physics. I've also been able to evaluate the eigenfrequency of the bridge in the absence of a magnetic field (with the bridge created using truss elements). But when I try to combine the two studies, I either get a string of errors, or no resonant response from the bridge.

My current model has a stationary study to evaluate the magnetic field, followed by an eigenfrequency study as a second step. Only the magnetic field physics is active in the first step, and only the truss physics is active in the second step. Each step also has it's own mesh. As far as I can tell, the settings are the same as when I evaluated each study separately and successfully. But when I plot the displacement of the bridge, it's just zero, and no eigenfrequency is given.

My model is attached - any comments or suggestions would be greatly appreciated. I'm thinking that I'm just missing some link between the two physics, or something.

Thanks!
Jillian