How to set a position-dependent Body Force in Ansys?

[mardom]

Hi to everyone,

I would like to know how to set a body force which depends on coordinates. I give you an example:

My domain is a free cylinder, but instead of a body force as gravity (which has the same value at every point of the volume), I want to set a body force which depends on the radius distance, F = A*r^2 (F will be 0 in the z-axis and maximum in the cylinder maximun radius). I also remind that r=sqrt(x^2+y^2)).

Then, summarizing:

1.- How should I set volume/body forces?

2.- How can make this body force position-dependent?

Thanks.

 

[Shu Jiang PEng SE]

I guess that you can apply rotation inertia force on the body.

 

[mardom]

Ok, it could be a solution. However, I was thinking about defining this force component-wise (Fx=A*sqrt(x^2+y^2)*x and Fy=A*sqrt(x^2+y^2)*y) in every node of the cylinder.

Do you agree with this solution?

Thnaks for your suggestion.

 

[Shu Jiang PEng SE]

To my understanding, the program calculates the inertia force on each nodes using the nodal mass defined in the mass matrix and other input information.

 

[mardom]

Can anybody tell me if it is possible to set variable the components of the acceleration vector?

 

[Mustaine3]

I know it is no direct help or answer to the question, but since it seems to be not possible in Ansys, you might check if you have access to Abaqus. There it is pretty simple to define gravity and body force with these formulas.

If only the initial position should be used, then it can be directly done in preprocessing with Abaqus/CAE.
If the load needs to be updated during the analysis (because of deformation, e.g.), then a Fortran subroutine can be created to do it.