Active DOF

[ansysUPF]

Could anyone be so kind to give a newbie, me, a short or detailed explaination of Active DOF? what is it? And how to use?

My problem: when I am using ANSYS to solve my problem, in the SOLU procedure, there is a warning said :
There are no active degrees of freedom.

SPARSE MATRIX DIRECT SOLVER.
Number of equations = 0, Maximum wavefront = 0

Thanks a lot!

 

[feadude]

I think you do not have loads or if you do they are applied on nodes that are restrained, therefore nodes can not move or rotate. It seems to be a boundary condition problem.

 

[johnhors]

Have you got a mesh ?

If yes, then has everything been completely restrained?

Have you had any training ???

 

[ansysUPF]

@feadude,
You are right, I deleted the calculating displacement transformation part in the program, there are 2 fixed nodes, but the others should have transformations on them.
I want to simplify the programm to the possiblly least.

@johnhors
I always have the right mesh, I just do some changes in the /SOLU part.
You are right, as I said I am a newbi;I got almost no training. and I learn ANSYS, eg. APDL, by digging out whenever necessary. I even not familiar with the use of GUI, and I can model only by writing simple input files.

I am in dangerous situation now.

Anyway, thank you both so much!

 

[ansysUPF]

Oh, I forgot to say: I do meshing with my own element, i.e, The input file for meshing is always the same. I modify the element quite often in order to get some valuable results to compare.