Force and Moment Convergence 1

[Nildev]

Hi,
Can anyone throw some light on when to use Force onvergence, Moment convergence or displacment convergence? How they are different and what is risk if we use only one?

 

[Drej]

See the CNVTOL command for a description of convergence parameters and their use within ANSYS. See the SOLCONTROL command for defaults in non-linear analysis. The base rule of thumb is that if your analysis is displacement controlled (U), choose convergence on F and/or M. You can use both if you want to be strict, or you can just narrow down the tolerance on one to some small value. In my experience, the default ANSYS-chosen parameters are usually more than sufficient for general purpose jobs.

 

[Nildev]

Hi Drej,

Thanks for the quick info. In one of my problem I had nlgeom,contacts and nonlinear mps. Problem was difficult to converge with default CNVTOL. I thought to relax. With only moment convergence(1e-4) very small I could get convergence. But Ansys recommndes F and M together. I would like to know what are implications of each one. How much difference in results(approximately) percentage one should expect by using different CNVTOL. Please let me know if you have any document on this. I had done my search on Ansys.net. I could not get any document on this.

Thanks.