What I seek is not in TFM, or I wouldn't be asking the help of the Xansys list. I know all about stiffness and how to adjust it; my application is a little more complicated than the average mechanical contact, however. It's a bone-implant interface, and there will be relative movement between the surfaces, that's how I know if the implant will osseointegrate or not. Assuming it does, I was looking at the possibility of using bonded contact with cohesive zone material to simulate loosening of the implant. The big problem with that technique is that I do not know what kind of mathematics trick Ansys uses in bonded contacts. I'm thinking it's probably a constraint equation between the contact points, but I need to be sure before I definitely write them off as a solution to my problem.
Thanks for trying, though... > Hi there. Its all given in TFM3.8 Real Constants. Contact tech is just > springs in normal,tangent and opening. > Its very hard to control and you must monitor all 3 directions and > adjust stiffness to whatever is > acceptable to you. Ideally there should be no relative movements in > the 3 directions, but for a deformable > contact this may be hard/impossible to achieve .Contact tech is > generally also an error source in results if the > mesh is coarse and not identical at both faces. > > I would advice you to run small test models to verify the contact > behaviour and stiffness tweaking until you > become familiar with what to do / (or not to do :) > > Brgds O.E.Lindoe, ImencoAS > > > > ----- Original Message ----- From: "Christiane Caouette" > > To: > Sent: Friday, May 02, 2008 9:02 PM > Subject: [Xansys] [STRUC] Bonded contacts > > >> >> Hello everyone, >> This is my first post; I hope I have done everything properly... >> My question is about bonded contacts: I have looked everywhere I could >> think of (ansys help, google, library...), but I haven't been able to >> find the mathematical description of these elements, only that of >> standard contact elements. So what does Ansys do to keep those bonded >> elements from opening? Is it a restriction on allowed nodal >> displacement? Like, they can't move out of the pinball region, or >> can't >> move relative to one another (target nodes vs contact nodes)? >> If anyone has any suggestions (or references I could check) to shed >> some light on this... thanks! >> Christiane Caouette, jr eng. >> PhD Student at Ecole de Technologie Superieure >> >> >> ^-------------------------------------------------------- >> | XANSYS - www.xansys.org | >> | The Discussion List for users of ANSYS, Inc. Software | >> | Hosted by PADT - www.padtinc.com | >> ^-------------------------------------------------------- > > >
_ _
^-------------------------------------------------------- | XANSYS - www.xansys.org | | The Discussion List for users of ANSYS, Inc. Software | | Hosted by PADT - www.padtinc.com | ^--------------------------------------------------------