Learning Forum

[Algodiz]

Hi!

I would like to know what's the difference between the edge force and surface Force in 2D Analysis.

I understand that the edge force represents the force in each node of the edge. But in the case of the surface force is not clear to me if this force represents the resultant force of the whole surface in each node of the edge, or the resultant force in the midpoint of the surface and is representated in the nodes of the edge, or something else.

I mean, if its the resultant of the surface's midpoint, this means that if we divide the value of the force by the length of the object this will give us the same value of the edge force right?

At the same time, what will be the difference between surface force and volume force in 3D Analysis?

Thanks in advance!

[Ashish Khemka]

Did you intend to put this question in the Electronics category?

Regards Ashish Khemka

[Algodiz]

yes!

[DELI]

Maxwell online help has more detailed explanation:
https://ansyshelp.ansys.com/Views/Secured/Electronics/v212/en/home.htm#../Subsystems/Maxwell/Content/ForceDensityQuantities.htm%3FTocPath%3DMaxwell%7CMaxwell%2520Help%7CPost%2520Processing%2520and%2520Generating%2520Reports%7CPlotting%2520Field%2520Overlays%7CPlotting%2520Standard%2520Fields%2520Overlays%7CPlotting%2520Standard%2520Field%2520Quantities%7C_____1
Edge force density is on a line, unit is N/m. Surface force density is on a sheet (or face), unit is N/m^2. Volume force density is on a volume, unit is N/m^3.

[Algodiz]

thank you for your answer. I understand what your are saying but my question was more related to how is the force in the model. So:
For a 2D Analyisis:
Edge force is representated in each node of the edge. (that's clear to me)
But in the case of the surface force which force is represented in the edge? (as the model is 2D, there is only one edge where the forces are representated instead of a surface)
Visually, the surface force is representated similar to the edge force as we see forces in each node of the edge. But this forces (the surface force) is of course different than the edge forces.
So my question is, what does this force (value) shows us?
For me, it was obvious to think that if, for instance, I multiply the edge force in one node times the length of the object (z axis) this will give me the surface force representated in that precise node. But this doesn't happen.
Can you please clarify me why is not the same?
Sorry if it's a stupid question, it's just that I am not able to visualize what kind of force is being representated for a Surface force density in a 2D model.

[DELI]

the surface force density is the force applied on the sheet in XY plane, and edge force density times the length of the object and you will get the surface force density on XZ or YZ plane. Those forces are not on the same thing, so results could be different.

[Algodiz]

Dear all, my conclusion is that for 2D analysis it is not recomended to use surface force density as it doesn't provide a trustable value. Thus, for 2D analysis is better to use Edge force density and Total force. For more info check the following reference: Łukaszewicz - 2012 - Analysis of local force distribution on stator surface in line start permanent magnet synchronous motor with U-shape