Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Contact Elements: Accuracy? 2

Status
Not open for further replies.

jargon5

Aerospace
Joined
Aug 11, 2005
Messages
27
Location
US
I have an assembly that I set "Global Contact", and have produced results that are marginally what I expected. Does anyone have any experience with the accuracy of Cosmos contact elements? I am used to NE/Nastran, and know the difficulty of assessing the actual phenomena when using this approach.
 
Hi,
well, yu're asking the impossible, I fear, since CW has only very marginal contact controls. I suppose it is using internal algorythms in order to set proper compenetration tolerance, pinball factor, normal rigidity factor, tangent stiffness factor and so on.
I would consider CWcontact results accurate as far as no high stress gradients are involved (I would be a bit suspicious in cases where surface/surface contact evolves towards edge/surface or even corner/surface contact because of the components' deformation: in these cases, at least the contact stiffness should be updated between timesteps, with consequent non-linear analysis, which is not the case with CW where the contact stiffness is calculated "at start" and then never updated).

Regards
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top