Contact in Ansys (WB)

[truckcab]

Hi all,
I am an old Nastran a Abaqus user just starting to use Ansys. At the present I have some problems in connection to contact modelling.

First of all; as a newbie I use WB. Eventually I guess I'll start using classic.

However, I have defined contact between two bodies whereof one of them is rigidly fixed and the orther one constrained in all other dofs apart from the loading direction. Initially, there is a small gap intended to be closed when the force is applied. I can not get this analysis to work out whatever I do. The moveable body just passes through the other as it did not exist. I have tried with smaller time increments, initial displacement in order to establish contact etc. etc. But I still can not get this to work. As far as I can see from the output written by the solver the the contacts do indeed exist but hmm... they do not work. The problem as is would have been no problem for me in Abaqus so I am convinced it is not the physics but rather me as a dilettant user of Ansys.

Any help in this subject would be most appreciated!

/Pierre



Live Long and Prosper !

 

[flash3780]

Have you tried adjusting the pinball size? ANSYS uses a "pinball region" to determine whether surfaces are about to come into contact. Workbench has a nice graphical display of the pinball size. If smaller load steps aren't working, perhaps adjusting the pinball size will.

Sidebar: Ansys Workbench defaults to using symmetric contact pairs, which I feel is unfortunate. They do so to help ensure that models converge, but it makes it difficult to interpret contact pressures. A single contact pair will run faster and be easier to interpret.
Also, the Augmented Lagrange contact formulation tends to be more accurate than the pure penalty method that Workbench uses by default. You may consider changing those options.

 

[ansysfreak]

What type of contact are you using? Frictionless?
Are you appling the load in 1 step?
Try to you set a number of substep to apply the load.