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plz, does anybody knows about this?

I am wondering if it makes sense to implement this in a COMSOL model or any FE model in general.

Do you have any interaction of the currents in the wire with the geometry in mind? Are the wires interacting by electric or magnetic fields? Is the resistance of the wires affected by their arrangement? And how do you specify the resistivity of the wires?

If it is just about static resistance within this network you could represent the wires by resistors proportional to their length in a circuit simulator like LT Spice.

Cheers
Edgar

Thanks Edgar for your kind answer,
actually the structure will go undet tension and I want to see the electrical resistance change during the tensile loading. thats the reason to do it in comsol.
two side of the structure are connected to a power supply and by loading the current changes in each section.
the structure is not made of wires, it is a cellular material so based on their diameter they have a specific resistance.

Thanks again,
Ehsan

Ehsan,

then you must implement the structure as physical domains, e.g. thin cylinders. The cylinder ends can be defined with a terminal BC and you can connect the terminals to a circuit physics node and measure impedances.

Cheers
Edgar

Dear Edgar,
do you mean using 3d elements? or I got it wrong.
I have touse 1D element(so just lines) because the model is huge and it will be very expensive to model it in 3D.

to use terminals as you said I have to use AC/DC lectrical circuit module?(I'm beginner in COMSOL, specially for electrical simulations)

thanks again
Ehsan

I think you can't do it with lines in a 3D model.

And yes, you can use the AC/DC circuit physics together with electrical currents.

Cheers
Edgar

Thanks Edgar for all your help :)

Saluti,
Ehsan

Hi Ehsan (and Edgar),

as there is hardly anything that can't be done in COMSOL there is also a solution for edge currents in 3D.

You can very easily use the coefficient form on edges to model that. The attached model shows a wire cube
(the kind that electrical engineering students at my study time needed to solder in their base practicals).

Two corners are connected to ground and a potential. The picture shows the potential and the current density.
For symmetry reasons one branch is completely current free.

If you want to wrap that equation into a physics interface you can also do that using the physics interface builder.

Best regards,
Sven

correction: two edges are current free

Hi Sven,

that's amazing, thank you for this one! I might as well have applications for that. I will really need to have a deeper look into the PDE interface. And you are right: saying "you can't do that" in COMSOL may sometimes be correct regarding a specific application module but mostly not in the context of complete COMSOL.

Cheers
Edgar

Dear Sven,
Thanks a lot for the model you sent. It solved my problem :)