Force calculations using Maxwell stress tensor in electrostatic field

[petersjohn]

Hello;

I am just beginning using ANSYS. I need to calculate force that acts on the surface of a sphere in an electrostatic field. My model is axis-symmetric. I have created an axis-symmetric 2D model and the computer calculated the electric field and the charges, etc on the surface of the sphere. I need to calculate the force on the surface of the sphere using Maxwell stress tensor. To do this I've done the following:

!code from pre-processor 
rsys,0
csys,11,0,0,0
nsel,loc,x,0.95*r,1.05*r
esln
cm,cname, [COLOR=red]!As I understand, now, I have to write some components of the elements, which?[/color]
fmagbc,'cname'

Solution works.
post-processor:
fmagsum,'cname' - here it says that the componenets of the elemetns are not selected thus fmagsum is equal 0.

Sincerely,

John

 

[meshparts]

Hello,

Looking at your code, I see you have already selected nodes and elements on nodes. I suppose you want to compute the magnetic force acting on those elements. For this you have to define an elements component:

cm,cname,elem

It is important that those elements are surrounded by air elements, see the help on fmagbc.

After solution, make sure that all elements are selected and then use fmagsum.

Regards
Alex

 

[petersjohn]

Thank you very much.

John